Methods and systems for draining cerebrospinal fluid into the venous system

ABSTRACT

Methods for treating hydrocephalus using a shunt, the shunt having one or more CSF intake openings in a distal portion, a valve disposed in a proximal portion of the shunt, and a lumen extending between the one or more CSF intake openings and the valve, the method comprises deploying the shunt in a body of a patient so that the distal portion of the shunt is at least partially disposed within a CP angle cistern, a body of the shunt is at least partially disposed within an IPS of the patient, and the proximal portion of the shunt is at least partially disposed within or proximate to a JV of the patient, wherein, after deployment of the shunt, CSF flows from the CP angle cistern to the JV via the shunt lumen at a flow rate in a range of 5 ml per hour to 15 ml per hour.

RELATED APPLICATION DATA

The present application is a continuation of U.S. patent applicationSer. No. 15/981,118, filed May 16, 2018, which is a continuation of U.S.Pat. No. 10,058,686, filed Jan. 4, 2018, which is a continuation of U.S.Pat. No. 10,279,154, filed Aug. 3, 2017, which is a continuation of U.S.Pat. No. 9,724,501, filed Feb. 14, 2017, which is a continuation of U.S.Pat. No. 9,669,195, filed Oct. 10, 2016, which is a continuation of U.S.Pat. No. 9,662,479, filed Jun. 28, 2016, which is a continuation of U.S.Pat. No. 9,387,311, filed Mar. 9, 2016, which is a divisional of U.S.patent application Ser. No. 14/929,066, filed Oct. 30, 2015, nowabandoned, which claims the benefit under 35 U.S.C. § 119 to U.S.Provisional Application Ser. No. 62/073,766, filed Oct. 31, 2014,62/142,895, filed Apr. 3, 2015, and 62/156,152, filed May 1, 2015. Theforegoing applications are hereby incorporated by reference into thepresent application in their entirety.

FIELD OF THE INVENTION

The present disclosure pertains generally to systems and methods foraccessing cerebral cisterns and draining cerebrospinal fluid (CSF),(e.g., to relieve elevated intracranial pressure), using an endovascularapproach. More particularly, the present disclosure pertains to systemsand methods for treatment of hydrocephalus, pseudotumor cerebri, and/orintracranial hypertension.

BACKGROUND

Hydrocephalus is one of the most common and important neurosurgicalconditions affecting both, children and adults. Hydrocephalus, meaning“water on the brain,” refers to the abnormal CSF accumulation in thebrain. The excessive intracranial pressure resulting from hydrocephaluscan lead to a number of significant symptoms ranging from headache toneurological dysfunction, coma, and death.

Cerebrospinal fluid is a clear, physiologic fluid that bathes the entirenervous system, including the brain and spinal cord. Cells of thechoroid plexus present inside the brain ventricles produce CSF. Innormal patients, cells within arachnoid granulations reabsorb CSFproduced in the choroid plexus. Arachnoid granulations straddle thesurface of the intracranial venous drainage system of the brain andreabsorb CSF present in the subarachnoid space into the venous system.

Approximately 450 mL to 500 mL of CSF is produced and reabsorbed eachday, enabling a steady state volume and pressure in the intracranialcompartment of approximately 8-16 cm H2O. This reabsorption pathway hasbeen dubbed the “third circulation,” because of its importance to thehomeostasis of the central nervous system.

Hydrocephalus occurs most commonly from the impaired reabsorption ofCSF, and in rare cases, from its overproduction. The condition ofimpaired reabsorption is referred to as communicating hydrocephalus.Hydrocephalus can also occur as a result of partial or completeocclusion of one of the CSF pathways, such as the cerebral aqueduct ofSylvius, which leads to a condition called obstructive hydrocephalus.

A positive pressure gradient between the intracranial pressure of thesubarachnoid space and the blood pressure of the venous system maycontribute to the natural absorption of CSF through arachnoidgranulations. For example, in non-hydrocephalic individuals ICPs canrange from about 6 cm H20 to about 20 cm H20. ICP greater than 20 cm H20is considered pathological of hydrocephalus, although ICP in some formsof the disease can be lower than 20 cm H20. Venous blood pressure in theintracranial sinuses and jugular bulb and vein can range from about 4 cmH20 to about 11 cm H20 in non-hydrocephalic patients, and can beslightly elevated in diseased patients. While posture changes inpatients, e.g., from supine to upright, affect ICP and venous pressures,the positive pressure gradient between ICP and venous pressure remainsrelatively constant. Momentary increases in venous pressure greater thanICP, however, can temporarily disturb this gradient, for example, duringepisodes of coughing, straining, or valsalva.

Normal pressure hydrocephalus (NPH) is one form of communicatinghydrocephalus. NPH patients typically exhibit one or more symptoms ofgait disturbance, dementia, and urinary incontinence, which can lead tomisdiagnosis of the disease. Unlike other forms of communicatinghydrocephalus, NPH patients may exhibit little or no increase in ICP. Itis believed that the CSF-filled ventricles in the brain enlarge in NPHpatients to accommodate the increased volume of CSF in the subarachnoidspace. For example, while non-hydrocephalic patients typically have ICPsranging from about 6 cm H20 to about 20 cm H20, ICPs in NPH patients canrange from about 6 cm H20 to about 27 cm H20. It has been suggested thatNPH is typically associated with normal intracranial pressures duringthe day and intermittently increased intracranial pressure at night.

Other conditions characterized by elevated intracranial pressure includepseudotumor cerebri (benign intracranial hypertension). The elevated ICPof pseudotumor cerebri causes symptoms similar to, but that are not, abrain tumor. Such symptoms can include headache, tinnitus, dizziness,blurred vision or vision loss, and nausea. While most common in obesewomen 20 to 40 years old, pseudotumor cerebri can affect patients in allage groups.

Prior art techniques for treating communicating hydrocephalus (and insome cases, pseudotumor cerebri) rely on ventriculoperitoneal shunts(“VPS” or “VP shunt” placement), a medical device design introduced morethan 60 years ago. VPS placement involves an invasive surgical procedureperformed under general anesthesia, typically resulting inhospitalization ranging from two to four days. The surgical proceduretypically involves placement of a silicone catheter in the frontal hornof the lateral ventricle of the brain through a burr hole in the skull.The distal portion of the catheter leading from the lateral ventricle isthen connected to a pressure or flow-regulated valve, which is placedunder the scalp. A separate incision is then made through the abdomen,into the peritoneal cavity, into which the distal portion of a tubingcatheter is placed. The catheter/valve assembly is then connected to thetubing catheter, which is tunneled subcutaneously from the neck to theabdomen.

VPS placement is a very common neurosurgical procedure, with estimatesof 55,000-60,000 VPS placements occurring in the U.S. each year. Whilethe placement of a VP shunt is typically well-tolerated by patients andtechnically straightforward for surgeons, VP shunts are subject to ahigh rate of failure in treated patients. Complications from VP shuntplacement are common with a one-year failure rate of approximately 40%and a two-year shunt failure rate reported as high as 50%. Commoncomplications include catheter obstruction, infection, over-drainage ofCSF, and intra-ventricular hemorrhage. Among these complications,infection is one of the most serious, since infection rates in adultsare reported between 1.6% and 16.7%. These VPS failures require “shuntrevision” surgeries to repair/replace a portion or the entirety of theVP shunt system, with each of these revision surgeries carrying the samerisk of general anesthesia, post-operative infection, and associatedcost of hospitalization as the initial VPS placement; provided, however,that shunt infections often cost significantly more, e.g., about threeto five times more, than the cost of the initial VP shunt placement.Often these infections require additional hospital stays where theproximal portion of the VPS is externalized and long-term antibiotictherapy is instituted. The rate of failure is a constant considerationby clinicians as they assess patients who may be candidates for VPSplacement. Age, existing co-morbidities and other patient-specificfactors are weighed against the likelihood of VP shunt failure that isvirtually assured during the first 4-5 years following initial VP shuntplacement.

Despite significant advances in biomedical technology, instrumentation,and medical devices, there has been little change in the design of basicVPS hardware since its introduction in 1952.

SUMMARY

Embodiments of the disclosed inventions include a method for treatinghydrocephalus using a shunt, the shunt having one or more cerebrospinalfluid (CSF) intake openings in a distal portion of the shunt, a valvedisposed in a proximal portion of the shunt, and a lumen extendingbetween the one or more CSF intake openings and the valve. The methodcomprises deploying the shunt in a body of a patient so that the distalportion of the shunt is at least partially disposed within acerebellopontine (CP) angle cistern of the patient, a body of the shuntis at least partially disposed within an inferior petrosal sinus (IPS)of the patient, and the proximal portion of the shunt is at leastpartially disposed within or proximate to a jugular vein (JV) of thepatient, wherein, after deployment of the shunt, CSF flows from the CPangle cistern to the JV via the shunt lumen at a flow rate in a range of5 ml per hour to 15 ml per hour.

In various embodiments of the method, deployment of the shunt comprises:introducing the shunt percutaneously through a venous access location inthe patient, delivering of the shunt so that the proximal portion of thedeployed shunt is disposed adjacent to a jugular bulb, advancing thedistal portion of the shunt from the IPS into the CP angle cistern usinga tissue penetrating member, and/or imaging the shunt while deployingthe shunt in the patient.

In other embodiments, the method includes that the distal portion of theshunt is expanded or self-expands from a collapsed deliveryconfiguration to an expanded deployed configuration as, or after, it isadvanced into the CP angle cistern. The tissue penetrating member iscoupled to a distal end of the shunt, and advancing the distal portionof the shunt from the IPS into the CP angle cistern comprises advancingthe tissue penetrating member and distal portion of the shunt through adura mater tissue wall of the IPS, and through an arachnoid tissuelayer, respectively, into the CP angle cistern. Further, duringadvancement of the distal portion of the shunt in this method, thedistal portion of the shunt is at least partially disposed in a deliverylumen of a delivery catheter, the tissue penetrating member comprises atissue penetrating tip of the delivery catheter, and advancing thedistal portion of the shunt from the IPS into the CP angle cisterncomprises advancing the delivery catheter so that the tissue penetratingtip penetrates through a dura mater tissue wall of the IPS, and throughan arachnoid tissue layer, respectively, into the CP angle cistern.

In some embodiments of the method, the delivery catheter includes adistal portion that assumes a curved configuration that guides thetissue penetrating tip into contact with the dura mater tissue at anangle in a range of 30 degrees to 90 degrees thereto. The distal portionof the delivery catheter comprises an expandable element or wall portionthat is expanded to cause the distal portion of the delivery catheter toassume the curved configuration. The expandable element or wall portioncomprises a balloon that is inflated to cause expansion thereof. Theballoon is inflated to a first expanded state causing the tissuepenetrating tip to engage the dura, and thereafter inflated to a secondexpanded state causing the tissue penetrating tip to penetrate throughthe dura and arachnoid tissue layers, respectively, into the CP anglecistern. The delivery catheter comprises one or more radiopaque markerslocated and dimensioned to indicate a position and orientation of thedistal portion of the delivery catheter when in the curvedconfiguration. In deploying the shunt, the method further compriseswithdrawing the distal portion of the delivery catheter from the CPangle cistern, while maintaining the distal portion of the shunt atleast partially disposed in the CP angle cistern.

In some embodiments, where the method of deployment of the shuntincludes advancing the distal portion of the shunt from the IPS into theCP angle cistern using a tissue penetrating member, the tissuepenetrating member comprising an elongate pusher member having a tissuepenetrating distal tip, the elongate pusher member extends though thevalve, lumen, and distal opening of the shunt, respectively, wherein theelongate pusher member is moveable relative to the shunt so that thetissue penetrating distal tip may be advanced out of, and withdrawninto, a distal opening of the shunt in communication with the lumen.Further, the method of advancing the distal portion of the shunt fromthe IPS into the CP angle cistern may include advancing the elongatepusher member so that the tissue penetrating distal tip penetratesthrough a dura mater tissue wall of the IPS, and through an arachnoidtissue layer, respectively, into the CP angle cistern, with the distalportion of the shunt being carried on the tissue penetrating member. Inthese embodiments, deploying the shunt further comprises, afteradvancing the distal portion of the shunt into the CP angle cistern,withdrawing the tissue penetrating member through the distal opening,lumen and valve of the shunt, respectively, wherein CSF flows throughthe respective distal opening, lumen and valve of the shunt afterwithdrawal of the tissue penetrating member.

In various embodiments of the method, the shunt comprises a firstengaging member protruding and/or extending radially inward from aninner wall of the shunt, the elongate pusher member comprises a secondengaging member protruding and/or extending radially outward towards theinner shunt wall, where the second engaging member engages the firstengaging member to thereby advance the distal portion of the shunt fromthe IPS into the CP angle cistern on the tissue penetrating member. Inthese embodiments, prior to advancing the tissue penetrating member intothe CP angle cistern, the method of deployment of the shunt furtherincludes adjusting a rotational orientation of the delivery catheterabout an axis of the delivery catheter so that the tissue penetratingdistal tip of the tissue penetrating member is thereafter advanced outof the distal opening of the delivery catheter into contact with thedura mater tissue at an angle in a range of 30 degrees to 90 degreesthereto.

In some embodiments of the method, deployment of the shunt furtherincludes advancing a delivery catheter into the IPS with the shunt andtissue penetrating member at least partially disposed in a deliverylumen of the delivery catheter, the delivery catheter having a distalopening in communication with the delivery lumen through which therespective tissue penetrating member and shunt may be advanced into theCP angle cistern.

In various embodiments of the method, deployment of the shunt includes:introducing the shunt into the patient's body while the shunt is atleast partially disposed in a delivery catheter, and where the deliverycatheter is advanced over a guidewire extending through a lumen of thedelivery catheter, which may be a same or different lumen in which theshunt is at least partially disposed, until a distal portion of thedelivery catheter is positioned in the IPS. The proximal portion of thedeployed shunt is at least partially disposed within, or proximate to,an intersection of a superior vena cava and right atrium of the patient.

In other embodiments of the method, the distal portion of the deployedshunt comprises a distal anchoring mechanism that positions the distalportion of the shunt so as to maintain the one or more CSF intakeopenings separated, apart and/or directed away from an arachnoid layerof the CP angle cistern; and/or the proximal portion of the deployedshunt comprises a proximal anchoring mechanism that positions theproximal portion of the shunt to thereby maintain a CSF outflow portand/or valve opening disposed in the proximal portion of the shuntseparated, apart and/or directed away from a wall of the JV.

Embodiments of the disclosed inventions include a method for relieving apatient's elevated intracranial pressure by implanting a shunt in thepatient, the shunt comprising one or more cerebrospinal fluid (CSF)intake openings in a distal portion of the shunt, a valve disposed in aproximal portion of the shunt, and a lumen extending between the one ormore CSF intake openings and the valve. The method comprises:introducing a deployment system including a tissue penetrating elementand the shunt from a venous access location in the patient; navigatingthe deployment system, including the penetrating element and shunt, fromthe venous access location to a target penetration site within aninferior petrosal sinus (IPS) of the patient, via a jugular vein (JV) ofthe patient; assessing a trajectory of the tissue penetrating element atthe target penetration site from the IPS into a cerebellopontine (CP)angle cistern of the patient; advancing the tissue penetrating elementthrough dura and arachnoid tissue layers at the target penetration site,and into the CP angle cistern; advancing the distal portion of the shuntinto the CP angle cistern through an opening in the respective dura andarachnoid tissue layers created by the tissue penetrating element;deploying a distal anchoring mechanism of the shunt in the CP anglecistern; withdrawing the delivery system from the target penetrationsite towards the JV, wherein the shunt is expelled from the deliverysystem and thereby deployed in the IPS as the delivery system iswithdrawn toward the JV; deploying a proximal anchoring mechanism of theshunt about a junction of the JV and IPS, such that the proximal portionof the shunt is oriented away from a medial wall of the JV; and removingthe delivery system from the patient, wherein the deployed shuntprovides a one-way flow path for CSF to flow from the CP angle cisternto the JV via the shunt lumen in order to maintain a normal differentialpressure between the patient's subarachnoid space and venous system.

In various embodiments, the method further comprises: confirming thatthe tissue penetrating element has accessed the CP angle cistern bywithdrawing CSF from the CP angle cistern through the delivery system,prior to withdrawing the delivery system from the patient′; and/orimaging the shunt while deploying the shunt in the patient.

In some embodiments of the method, the proximal portion of the deployedshunt is disposed adjacent to a jugular bulb; and/or the distal portionof the shunt is expanded or self-expands from a collapsed deliveryconfiguration to an expanded deployed configuration as or after it isadvanced into the CP angle cistern. In further embodiments of themethod, the delivery system comprises a delivery catheter, and thetissue penetrating element comprises a tissue penetrating tip of thedelivery catheter, wherein advancing the distal portion of the shuntinto the CP angle cistern comprises advancing the delivery catheter intothe CP angle cistern with the shunt positioned in a lumen of thedelivery catheter.

In various embodiments of the method, the delivery catheter comprises adistal portion that assumes a curved configuration that guides thetissue penetrating tip into contact with the dura mater tissue at anangle in a range of 30 degrees to 90 degrees thereto; the distal portionof the delivery catheter comprises an expandable element or wall portionthat is expanded to cause the distal portion of the delivery catheter toassume the curved configuration; the expandable element or wall portioncomprises a balloon that is inflated to cause expansion thereof; theballoon is inflated to a first expanded state causing the tissuepenetrating tip to engage the dura, and thereafter inflated to a secondexpanded state causing the tissue penetrating tip to penetrate throughthe dura and arachnoid tissue layers, respectively, into the CP anglecistern. In the embodiments of the method, the delivery cathetercomprises one or more radiopaque markers located and dimensioned toindicate a position and orientation of the distal portion of thedelivery catheter when in the curved configuration.

In some embodiments of the method, the tissue penetrating elementcomprises an elongate pusher member having a tissue penetrating tip, theelongate pusher member extending though the valve, lumen, and distalopening of the shunt, respectively, wherein the elongate pusher memberis moveable relative to the shunt so that the tissue penetrating distaltip may be advanced out of, and withdrawn into, a distal opening of theshunt in communication with the shunt lumen, wherein the distal portionof the shunt is advanced into the CP angle cistern on the elongatepusher member. In these embodiments, the delivery system comprises adelivery catheter having a lumen in which the respective shunt andelongate pusher member are at least partially disposed when the tissuepenetrating tip of the elongate pusher member is advanced through therespective dura and arachnoid tissue layers, the method furthercomprising withdrawing the elongate pusher member through the distalopening, lumen and valve of the shunt, respectively, after the distalportion of the shunt is advanced into the CP angle cistern, wherein CSFflows through the respective distal opening, lumen and valve of theshunt after withdrawal of the elongate pusher member.

In some embodiments, the method further comprises adjusting a rotationalorientation of the delivery catheter about an axis of the deliverycatheter so that the tissue penetrating tip of the elongate pushermember is thereafter advanced out of a distal opening of the deliverycatheter into contact with the dura mater tissue at an angle in a rangeof 30 degrees to 90 degrees thereto, prior to advancing the tissuepenetrating tip of the elongate pusher member into the CP angle cistern.

In various embodiments of the method, the proximal portion of thedeployed shunt is at least partially disposed within, or proximate to,an intersection of a superior vena cava and right atrium of the patient,and/or the deployed distal anchoring mechanism positions the distalportion of the shunt so as to maintain the one or more CSF intakeopenings separated, apart and/or directed away from an arachnoid layerof the CP angle cistern.

Embodiments of the disclosed inventions include a method for treatingnormal pressure hydrocephalus (NPH) using a shunt, the shunt comprisingone or more cerebrospinal fluid (CSF) intake openings in a distalportion of the shunt, a valve disposed in a proximal portion of theshunt, and a lumen extending between the one or more CSF intake openingsand the valve, the lumen having an inner diameter in a range of 0.008″to 0.014″. The method comprises: deploying the shunt in a body of an NPHpatient so that the distal portion of the shunt is at least partiallydisposed within a cerebellopontine (CP) angle cistern of the patient, abody of the shunt is at least partially disposed within an inferiorpetrosal sinus (IPS) of the patient, and the proximal portion of theshunt is at least partially disposed within, or proximate to, a jugularvein (JV) of the patient, wherein the shunt valve opens at a pressuredifferential between the CP angle cistern and JV in a range of 3 mm Hgto 5 mm Hg, so that, after deployment of the shunt, CSF flows from theCP angle cistern to the JV via the shunt lumen.

Other and further aspects and features of embodiments will becomeapparent from the ensuing detailed description in view of theaccompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a head of a human patient;

FIG. 2 is a cross-sectional view of a portion of the head of a humanpatient;

FIG. 3A is a cross-sectional view of a deployed endovascular shuntaccording to embodiments of the disclosed inventions;

FIG. 3B is a side view of a delivery assembly according to embodimentsof the disclosed inventions;

FIGS. 4A-D are cross-sectional views of deployment of endovascular shuntaccording to embodiments of the disclosed inventions;

FIGS. 5A-J are side and cross-sectional views of deployment of anendovascular shunt according to another embodiment of the disclosedinventions;

FIG. 6 is a cross-sectional view of an endovascular shunt according toembodiments of the disclosed inventions;

FIGS. 6A-T are side and cross-sectional views of features of theendovascular shunt of FIG. 6 according to embodiments of the disclosedinventions;

FIG. 7 is a cross-sectional view of an endovascular shunt and a catheterinterface according to embodiments of the disclosed inventions;

FIG. 8 is a cross-sectional view of an endovascular shunt according toembodiments of the disclosed inventions;

FIG. 9 is cross-sectional view of an endovascular shunt according toanother embodiment of the disclosed inventions;

FIG. 10 is a cross-sectional view of a delivery catheter according toembodiments of the disclosed inventions;

FIGS. 11A-C are cross-sectional views of distal portions of anendovascular and/or catheters, including experimental data, according toembodiments of the disclosed inventions;

FIG. 12 is a cross-sectional view of a deployed endovascular shunt and aconduit according to embodiments of the disclosed inventions;

FIGS. 13A-13C are side views of prior art self-expanding stent-grafts;

FIGS. 14A-14H are side and cross-sectional views of deployment of aconduit and an endovascular shunt according to yet another embodiment ofthe disclosed inventions;

FIGS. 15A-15D are cross-sectional and side views of deployment anendovascular shunt according to one embodiment of the disclosedinventions;

FIG. 16 is a side view of a deployed endovascular shunt according toanother embodiment of the disclosed inventions;

FIGS. 17A-B are cross-sectional views of an endovascular shunt having apre-curved configuration according to one embodiment of the disclosedinventions;

FIGS. 18A-B are cross-sectional views of an endovascular shunt havingselective slots according to another embodiment of the disclosedinventions;

FIGS. 19A-B are cross-sectional views of an endovascular shunt having aelongate member according to yet another embodiment of the disclosedinventions;

FIGS. 20A-F are cross-sectional views of an endovascular shunt deliveryassembly having an end cap and an stabilizing member accordingembodiments of the disclosed inventions;

FIGS. 21A-E are cross-sectional views of another endovascular shuntdelivery assembly having a deflecting element and a stabilizing memberaccording embodiments of the disclosed inventions;

FIGS. 22A-G are side and cross-sectional views of a deployedendovascular shunt according to another embodiment of the disclosedinventions;

FIGS. 23A-E are side and cross-sectional views of a deployedendovascular shunt according to another embodiment of the disclosedinventions;

FIGS. 24A-E are side views of deployed endovascular shunts according toothers embodiments of the disclosed inventions;

FIGS. 25A-G are side and cross-sectional views of a deployedendovascular shunt according to yet another embodiment of the disclosedinventions;

FIGS. 26A-G are side and cross-sectional views of a deployedendovascular shunt according to another embodiment of the disclosedinventions;

FIGS. 27A-E are side and cross-sectional views of a deployedendovascular shunt according to another embodiment of the disclosedinventions;

FIG. 28 is a side view of a deployed endovascular shunt according to oneembodiment of the disclosed inventions;

FIGS. 29A-G are side and cross-sectional views of an alternativeembodiment of the shunt constructed and implanted according toembodiment of FIGS. 12 and 14A-H of the disclosed inventions;

FIGS. 30A-F are side and cross-sectional views of a deployedendovascular shunt according to another embodiment of the disclosedinventions;

FIG. 31 is a side view an alternative embodiment of the shuntconstructed and implanted according to the embodiment of FIGS. 22A-G ofthe disclosed inventions;

FIG. 32 is a side view an alternative embodiment of the shuntconstructed and implanted according to embodiment of FIG. 21E of thedisclosed inventions;

FIGS. 33A-33C are cross-section views of a surgical tool and anendovascular shunt interface according to embodiments of the disclosedinventions;

FIGS. 34A-34B are cross-section views of an endovascular shunt accordingto another embodiment of the disclosed inventions;

FIG. 35 is a perspective view of a system for testing penetratingcomponents of the endovascular shunt delivery assembly according toembodiments of the disclosed inventions;

FIG. 36 is a perspective view of a tissue block of the system of FIG.35;

FIG. 37 is a perspective view of the tissue block shown in FIG. 36;

FIG. 38 is a side view of a penetration test of the system of FIG. 35;

FIG. 39 is an experimental data table according to embodiments of thedisclosed inventions;

FIG. 40 is a schematic flow diagram of an exemplary method of assessingthe patency of an implanted shunt according to the disclosed inventions;

FIG. 41 is a schematic flow diagram of another exemplary method ofassessing the patency of an implanted shunt according to the disclosedinventions;

FIGS. 42A-B are cross-sectional views of a deployed endovascular shuntaccording to embodiments of the disclosed inventions;

FIGS. 43A-D are perspective, side and cross-sectional views of adelivery catheter, according to one embodiment of the disclosedinventions;

FIGS. 44A-E are side and cross-sectional views of the creation ofanastomosis using the delivery catheter of FIGS. 43A-D;

FIGS. 45A-D are side and cross-sectional views of a piercing elementconstructed according to one embodiment of the disclosed inventions;

FIGS. 46A-G are side and cross-sectional views of a piercing elementconstructed according to another embodiment of the disclosed inventions;

FIGS. 47A-50B are perspective, side and cross-sectional views of anexpandable balloon constructed according to various embodiments of thedisclosed inventions;

FIGS. 51A-54C are perspective, side and cross-sectional views ofpiercing elements constructed according to various embodiments of thedisclosed inventions;

FIGS. 55A-55E are perspective, side and cross-sectional views of cuts inthe elongated body of the shunt, constructed according to one embodimentof the disclosed inventions;

FIGS. 56A-60C are perspective and side views of patterns of the cuts inthe elongated body of the shunt, constructed according to variousembodiments of the disclosed inventions;

FIGS. 61A-D are side and cross-sectional views of an alternativeembodiment of the shunt having a piercing element cover, constructedaccording to one embodiment of the disclosed inventions;

FIGS. 62A-D are cross-sectional views of a shuttle element for coveringpiercing elements during delivery of the shunt, according to anembodiment of the disclosed inventions;

FIGS. 63A-G are perspective and cross-sectional views of an endovascularshunt according to yet another embodiment of the disclosed inventions;

FIGS. 64A-C are cross-sectional views of a distal anchoring mechanism ofan endovascular shunt according embodiments of the disclosed inventions;

FIGS. 65A-E are perspective, side and cross-sectional views of adelivery catheter, according to another embodiment of the disclosedinventions;

FIG. 66 is a perspective views of a guidewire, according to oneembodiment of the disclosed inventions; and

FIGS. 67A-D are cross-sectional views of delivery catheters, accordingembodiments of the disclosed inventions.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about,” whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skilled in the art wouldconsider equivalent to the recited value (i.e., having the same functionor result). In many instances, the terms “about” may include numbersthat are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

Various embodiments are described hereinafter with reference to thefigures. The figures are not necessarily drawn to scale, the relativescale of select elements may have been exaggerated for clarity, andelements of similar structures or functions are represented by likereference numerals throughout the figures. It should also be understoodthat the figures are only intended to facilitate the description of theembodiments, and are not intended as an exhaustive description of theinvention or as a limitation on the scope of the invention, which isdefined only by the appended claims and their equivalents. In addition,an illustrated embodiment needs not have all the aspects or advantagesshown. An aspect or an advantage described in conjunction with aparticular embodiment is not necessarily limited to that embodiment andcan be practiced in any other embodiments even if not so illustrated.

References herein to the term “endovascular,” such as endovascular shuntor endovascular approach, generally refer to minimally-invasive devices,systems, and procedures configured for introduction into a patient'svasculature through a small access device (e.g., needle or introducersheath) without a large incision or open surgical procedure, and usingthe vasculature to guide various catheters, shunts, and other systemelements described herein percutaneously to a target procedural locationdisposed within or about the patient's vasculature (e.g., intracranialvenous sinuses). It should be appreciated that the terms implantingand/or deploying, and the terms implanted and/or deployed, are usedinterchangeably herein. Additionally, the terms member or element areinterchangeably herein.

FIG. 1 is a schematic diagram showing the head 100 of a human patient.Within each side of the patient's head, an inferior petrosal sinus (IPS)102 connects a cavernous sinus (CS) 104 to a jugular vein 106 and/or ajugular bulb 108. For clarity, the acronym “IPS” is used herein to refergenerally to the inferior petrosal sinus and more particularly to theinterior space (or lumen) of the inferior petrosal sinus. The IPS 102facilitates drainage of venous blood into the jugular veins 106. In somepatients, the junction of the IPS 102 and the jugular vein 106 occurswithin the jugular bulb 108. However, in other patients, this junctioncan occur at other locations in the jugular vein 106. Moreover, whilethe IPS 102 in FIG. 1 is a single sinus passageway, in some patients theIPS can be a plexus of separate channels that connect the CS to jugularvein 106 (not shown) and/or jugular bulb 108.

Embodiments of the disclosed inventions are described with respect to atarget penetration site in the IPS 102 to access the CSF-filledcerebellopontine (CP) angle cistern 138, which provide a conduit for CSFto flow from the subarachnoid space 116 into the jugular bulb 108,jugular vein 106, and/or the superior vena cava-right atrium junction105 (FIGS. 1, 2, and 42B). The delivery assemblies and shunts describedherein can access the target penetration site in the IPS 102 through avenous access location in the patient. The delivery assemblies andshunts described herein can penetrate the dura mater IPS wall 114 andthe arachnoid layer 115 to access the CP angle cistern 138 from within asuperior petrosal sinus (SPS) 122 (FIGS. 1 and 2) for delivery andimplantation of the shunt at the target site. The dura mater IPS wall114 is also referred to herein as the dura IPS wall 114, or simply asthe IPS wall 114. The SPS is a small diameter venous sinus that connectsfrom the sigmoid sinus (distally located to jugular bulb 108) to thecavernous sinus 104 (FIG. 1). Further, the delivery assemblies andshunts described herein can be advanced through the IPS 102 and into thecavernous sinus 104, so that an anastomosis (not shown) can be createdin the upper portion or roof of the cavernous sinus 104 to access theCSF-filled suprasellar cistern 148, shown in FIG. 1, for implantation ofthe shunt at such target site. Whether penetration to access a targetsite, deployment and implantation of a shunt occurs from the lumen ofthe SPS or cavernous sinus to access CSF in the subarachnoid space, theembodiments of the inventions described herein provide a conduit for CSFto flow from the subarachnoid space into the jugular bulb 108, jugularvein 106, and/or the superior vena cava-right atrium junction 105.

FIG. 2 shows a cross-sectional view of a portion of head 100, includingIPS 102, jugular vein 106, and jugular bulb 108. In addition, basilarartery 110, brain stem 112, pia 112 a, and IPS wall 114 are also shownin FIG. 2. The IPS is a relatively small diameter intracranial venoussinus that facilitates drainage of cerebral venous blood into thejugular vein; the IPS is formed by a cylindrical layer of dura mater,typically about 0.9 mm to 1.1 mm thick for the portion of IPS wall 114shown in FIG. 2, which creates a hollow lumen through which blood flows.In the cross-section view of FIG. 2, the hollow lumen of the IPS residesbetween upper IPS wall 114 and a lower IPS wall 117, also comprised ofdura mater; the IPS itself lies in a bony groove or channel in theclivus bone (not shown) beneath IPS wall 117 in FIG. 2.

A cross-section of the IPS 102 orthogonal to the plane depicted in FIG.2 would show that the cylindrical layer of dura mater forming IPS 102 issurrounded by bone for about 270 degrees of its circumference with theremaining portion of the IPS circumference (i.e., IPS wall 114 in FIG.2) covered by arachnoid matter 115 and facing CP angle cistern 138.Arachnoid mater 115 (also referred to herein as the arachnoid tissuelayer or the arachnoid layer) is a delicate and avascular layer,typically about 0.05 mm to 0.15 mm thick, that lies in direct contactwith the dura mater comprising the exterior of IPS wall 114; arachnoidlayer 115 is separated from the pia mater surrounding brain stem 112 bythe CSF-filled subarachnoid space 116 (e.g., CP angle cistern 138). Thelower portion of the IPS 102, opposite to the IPS wall 114 is the IPSwall 117 formed by dura mater that sits in a channel in the clivus bone(not shown).

It should be appreciated that for the embodiments of the disclosedinventions, the methods and devices are configured to create ananastomosis via an endovascular approach by piercing or penetrating fromwithin the hollow IPS 102 to pass through the dura of IPS wall 114, andcontinue penetrating through the arachnoid layer 115 until reaching theCSF-filled subarachnoid space 116 (e.g., CP angle cistern 138). For easeof illustration, it should be appreciated that the arachnoid matter 115covering the IPS wall 114 is present, although, not shown in certainfigures.

The diameter d₁ of IPS 102 is approximately 3 mm but can range fromapproximately 1 mm to about 6 mm. As shown in FIG. 2, at the junction118 between the IPS 102 and the jugular bulb 108 and/or jugular vein106, the diameter d₂ of the IPS 102 can narrow. For example, d₂ isapproximately 2 mm, but can be as small as about 0.5 mm. The length ofthe IPS 102 from the junction 118 with the jugular vein 106 to thecavernous sinus 104 (shown in FIG. 1) is approximately in a rangebetween 3.5 cm to 4 cm.

As shown in FIG. 1, most patients have two IPS 102 and two jugular veins106 (left and right). In a very small percentage of patients (e.g., lessthan 1%), there is no connection between one IPS and the correspondingjugular vein. It is highly unlikely, however, that any given patientwill lack connections to the corresponding jugular veins on both leftand right IPS.

Subarachnoid spaces are naturally occurring separations between the piamater and the arachnoid layer where the CSF pools. Typically, the CSF ispassed into a subarachnoid space over the cerebral hemispheres and theninto the venous system by arachnoid granulations. The subarachnoid space116 in FIG. 2 corresponds to a cerebellopontine (CP) angle cistern 138,which acts as a reservoir for CSF. In patients with hydrocephalus, abuild-up of CSF within the CP angle cistern 138 (in addition to othercisterns) can occur, for example, if patients lack properly functioningarachnoid granulations. If the excess CSF is not removed, the resultingexcess intracranial pressure can lead to symptoms such as headache,neurological dysfunction, coma, and even death.

FIG. 3A illustrates an exemplary endovascular shunt 200 implanted in theIPS 102 according to the embodiments of the disclosed inventions. Theshunt 200 is delivered and implanted into a patient percutaneously via acatheter inserted into the venous system of the body through a needlehole (e.g., in the femoral or jugular vein), without requiring boringinto a patient's skull, general anesthesia, or other open surgicaltechniques. The shunt 200 includes a tubular configuration having aproximal portion 204, an elongate body 203, a distal portion 202, and aninner lumen 207 extending therebetween. When the shunt 200 is implantedin a target site of the patient (e.g., inferior petrosal sinus), thedistal portion 202 of the shunt has accessed and is at least partiallydisposed in the CSF-filled CP angle cistern 138, so that the body 203 ofthe shunt 200 is disposed in the IPS 102, and the proximal portion 204is at least partially disposed in the jugular bulb 108 and/or thejugular vein 106. The implanted shunt 200 provides a fluid communicationbetween the CP angle cistern 138 into the jugular bulb 108 and/orjugular vein 106 so that CSF is drained through the lumen 207 of theshunt 200 from the subarachnoid space 116 to the venous system (e.g.,jugular vein 106). When the shunt 200 is deployed at the target site,CSF enters the distal intake opening 251 (FIG. 6), flows through thelumen 207, and exits out the proximal opening 205 (FIG. 6) of the shunt200.

Shunt 200 capitalizes on a favorable pressure gradient between thesubarachnoid space 116 and venous system (e.g., jugular vein 106) todrive CSF through the lumen 207. In patients without hydrocephalus, thenormal differential pressure between the intracranial pressure of thesubarachnoid space 116 (e.g., CP angle cistern) and blood pressure ofthe venous system (e.g., IPS or jugular vein) is about 5 to 12 cm H2O;this differential pressure between the subarachnoid space and venoussystem can be significantly higher in hydrocephalic patients. Oncedeployed and implanted, the shunt 200 facilitates one-way flow of CSFfrom the CP angle cistern 138 into the jugular bulb 108 and/or jugularvein 106 where CSF is carried away by venous circulation, similar to theway that normally functioning arachnoid granulations drain CSF into thevenous system. Shunt 200 prevents backflow of venous blood through innerlumen 207 into subarachnoid space 116 via one or more one-way valves orother flow regulating mechanisms described herein. The shunt 200 allowsfor a more physiologic drainage of CSF by directing CSF into thecerebral venous system, a process that occurs naturally in peoplewithout hydrocephalus. In this manner, the pressure created by theexcess CSF in the subarachnoid space 116 is relieved, and patientsymptoms due to hydrocephalus can thereby be ameliorated or eveneliminated. The shunt 200 may also include a flow regulating mechanism209 configured to regulate fluid flow through the shunt lumen 207.

The IPS 102 anatomy supports long-term stability of the shunt 200relative to other locations potentially suitable for endovascular shuntdeployment for treating hydrocephalus. Particularly, the relatively longlength and narrow diameter of the IPS 102 (compared to other venoussinuses) provides a natural housing for the shunt 200. The foundationprovided by the grooved portion of the clivus bone that surrounds abouttwo-thirds of the IPS circumference further supports long-term stabilityof the shunt 200, and presents a stable platform that delivery systemsdisclosed herein can leverage during shunt implant procedures. Proximityto a well-established, CSF-filled cistern such as the CP angle cistern138 further supports IPS 102 as a preferred implant location compared toother endovascular shunting techniques. Moreover, occlusion of the IPS102 from shunt 200 placement represents little to no risk for thepatient, as the IPS 102 plays a relatively unimportant role in theoverall intracranial venous blood circulation scheme unlike largerdiameter dural venous sinuses such as the sagittal sinus, sigmoid sinus,straight sinus, and transverse sinus.

The proximal portion 204 of the deployed shunt 200 that extends from thejunction 118 into the jugular bulb 108 and/or the jugular vein 106 maybe in a range between 1 mm to 5 mm (e.g., 2-3 mm), or any other suitablelength configured to extend into the jugular bulb 108 and/or the jugularvein 106 from the junction 118. The proximal portion 204 of the deployedshunt 200 is disposed adjacent to the jugular bulb 108. The circulationof venous blood flow around the proximal portion 204 of the shunt 200,disposed in the jugular bulb 108 and/or the jugular vein 106, constantlyand gently agitates the proximal portion 204, minimizing, deterring oravoiding growth of endothelial cells and clogging of the lumen 207opening 205 at the proximal portion 204 of the shunt 200. Venous bloodflow rates in jugular vein 106 can be significantly higher than theblood flow rates in larger diameter dural venous sinuses (i.e.,sagittal, sigmoid, straight, transverse), which favor long-term shuntpatency of the disclosed embodiments.

Alternatively, the proximal portion 204 of the shunt 200 further extendsfrom the jugular vein 106 and/or jugular bulb 108 into the superior venacava-right atrium junction 105, in one or more embodiments of thedisclosed inventions, as shown in FIGS. 42A-B. In such embodiments, theimplanted shunt 200 is configured to extend from the CP angle cistern138 through IPS 102 and jugular vein 106 into the right atrium 107 ofthe heart 109 (FIG. 42A); particularly, the proximal portion 204 havingthe proximal opening 205 in communication with the lumen 207 of theshunt 200, and/or the valve 209, is disposed at the junction 105 betweenthe superior vena cava 101 and the right atrium 107 of the heart 109,preventing or avoiding extending into the right atrium 107 (FIG. 42B).Alternatively or additionally, the shunt 200 can include a tubularextension 204′ (e.g., silicone or other biocompatible material catheteror the like) coupled to the proximal portion 204 of the shunt 200disposed in the jugular vein 106 and/or jugular bulb 108, so that theproximal portion 204 further extends into the superior vena cava-rightatrium junction 105. In this embodiment, the proximal portion 204 of thedeployed shunt 200 is at least partially disposed within, or proximateto, an intersection of a superior vena cava and right atrium of thepatient. In such embodiments, the extended proximal portion 204, 204′ ofthe shunt 200 relies on turbulent blood flow proximate to the superiorvena cava-right atrium junction 105 to maintain patency and avoidclogging (e.g., by endothelial cell ingrowth) of the extended proximalportion 204, 204′ of the shunt 200. In this embodiment, the valve 209can be disposed in the extended proximal portion 204, 204′ within thesuperior vena cava-right atrium junction 105.

The implanted shunt 200 may not occlude the IPS 102, for example, whenthe diameter of the shunt 200 is smaller than the diameter of the IPS102, so that venous blood flow continues through the IPS 102 into thejugular vein 106. Alternatively, the implanted shunt 200 may occlude theIPS 102 preventing venous blood flow from the cavernous sinus into thejugular vein 106. However, it has been observed that an occluded IPS,whether resulting from a surgical procedure or thrombosis, typically hasno impact on a patient's venous circulatory function.

FIG. 3B is a side view of a delivery assembly 300 for delivering theshunt 200 into a target site of a patient, constructed in accordancewith embodiments of the disclosed inventions. The delivery assembly 300includes the shunt 200 detachably coupled to the delivery assembly 300.The delivery assembly 300 and shunt 200 may be composed of suitablebiocompatible materials. The delivery assembly 300 is dimensioned toreach remote locations of the vasculature and is configured to deliverthe shunt 200 percutaneously to the target location (e.g., inferiorpetrosal sinus). The delivery assembly 300 includes a tubular memberinterface having an outer tubular member 320 (i.e., guide catheter) andan inner tubular member 304 (i.e., delivery catheter/microcatheter)coaxially disposed within the outer tubular member 320 and movablerelative to the outer tubular member 320. The delivery assembly 300 mayinclude a guidewire 302 coaxially disposed within the guide catheter 320and/or the delivery catheter 304. The guidewire 302 can be, for example,0.035 inches (0.889 mm) in diameter. Additionally to the guidewire 302,the delivery assembly 300 may include a delivery guidewire 308 disposedwithin the delivery catheter 304. The delivery guidewire 308 has asmaller diameter (e.g., approximately 0.010 inches-0.254 mm- to 0.018inches-0.4572 mm-) compared to guidewire 302.

The guide catheter 320, delivery catheter 304, and guidewires 302/308may be formed of suitable biocompatible materials, and may includemarkings for purposes of imaging (e.g., markers composed of radio-opaquematerials). Further, the delivery catheter 304 may include one or moreanchoring mechanisms disposed along the body of the catheter allowingtemporary anchoring of the catheter 304 within IPS 102 during thedeployment of the shunt 200. The anchoring mechanisms configuration andactuation may be similar as the anchoring mechanisms of the shunt 200described in further detail below. For example, the anchoring mechanismof the delivery catheter 304 may be actuated (e.g., engagement anddisengagement within the IPS 102) using a guidewire.

Various known and often necessary accessories to the delivery assembly300, e.g., one or more radiopaque marker bands 13 at the distal portion324 of the guide catheter 320 to allow viewing of the position of thedistal portion under fluoroscopy and a Luer assembly 17 for guidewiresand/or fluids access, are shown in FIG. 3B.

The delivery assembly 300 may include a tissue penetrating element 306coaxially disposed within the delivery catheter 304 and/or guidecatheter 320 and/or shunt 200. The tissue penetrating element 306 isconfigured to pierce the IPS wall 114 and arachnoid layer 115 to accessthe CP angle cistern 138 for implantation of the shunt 200.Alternatively, the shunt 200 includes a tissue penetrating member 250 onthe distal portion 202 of the shunt 200′ (e.g., FIGS. 5C-I and FIGS.14F-H), so the tissue penetrating element 306 is not required in thedelivery assembly 300, since the tissue penetrating member 250incorporated in the shunt 200′ is configured to pierce the IPS wall 114and arachnoid layer 115. (For ease in illustration, the variousembodiments of the shunt disclosed and illustrated herein are given thereference number 200 or 200′, although the embodiments may differ fromeach other in certain aspects and features.)

FIGS. 4A-4D illustrate an exemplary method of delivering the shunt 200into the target site (e.g., inferior petrosal sinus) to drain CSF from acistern in the subarachnoid space 116 (e.g., CP angle cistern 138) inaccordance with embodiments of the disclosed inventions. After gainingaccess to the vasculature of a patient (e.g., via the femoral vein orthe jugular vein 106), the guide catheter 320 and/or the guidewire 302of the delivery assembly 300 may be advanced through the vasculatureinto the IPS 102 or a location proximate to the IPS 102 and IPS wall114. When the guidewire 302 is used for navigation of the deliveryassembly 300 into the target site, the guidewire 302 is further advancedto establish a pathway along which the delivery assembly 300 may beadvanced. After the guidewire 302 has been positioned in a desiredlocation, the guide catheter 320 may be advanced over the guidewire 302,so that a distal portion 324 of guide catheter 320 is within the jugularbulb 108, near the junction 118 between the IPS 102 and jugular vein106. Alternatively, the guide catheter 320 may be advanced to thelocation near the junction 118, and the guidewire 302 is furtheradvanced into the IPS 102. In a further alternative method, the guidecatheter 320 is advanced to the desired location near the junction 118without the use of the guidewire 302.

With the guide catheter 320 positioned at or about the junction 118between jugular vein 106 and IPS 102, as shown in FIG. 4B, the deliverycatheter 304 and the delivery guidewire 308, disposed within thedelivery catheter 304, are advanced within the guide catheter 320. Thedelivery catheter 304 and delivery guidewire 308 are further advanced tothe distal portion 324 of guide catheter 320, which is located in thejugular vein 106. The delivery guidewire 308 is then passed through thejunction 118 between jugular vein 106 and IPS 102 and into the openingof IPS 102 in the medial wall of the jugular dome. The deliveryguidewire 308 is then further advanced within IPS 102 to the posterioraspect of the cavernous sinus. The distal portion 334 of deliveryguidewire 308 may be more flexible than other portions of the deliveryguidewire 308 to facilitate navigation into the IPS 102 from jugularvein 106 and into the cavernous sinus.

Next, the delivery catheter 304 is advanced over the delivery guidewire308 and into IPS 102. Advancement of delivery catheter 304 continuesuntil a distal portion 344 of delivery catheter 304 is positionedadjacent or proximate to a desired point on IPS wall 114 where the shunt200 is to be inserted to form an anastomosis between the CP anglecistern 138 and the lumen of IPS 102. Alternatively, the deliveryguidewire 308 and the delivery catheter 304 may be advancedincrementally and sequentially into the opening of the IPS 102 atjunction 118 and through one or more portions of the IPS 102.

Once the delivery guidewire 308 and delivery catheter 304 are located ata desired location within the IPS 102 for shunt deployment, the deliveryguidewire 308 can be advanced to the posterior aspect of the cavernoussinus. The delivery guidewire 308 can serve as a support for thedelivery catheter 304 within the IPS 102 and for shunt 200 deployment.

A variety of different imaging methods can be used to ensure accuratepositioning of the shunt 200, guide catheter 320, guidewire 302,delivery catheter 304, and/or delivery guidewire 308, described above.Examples of suitable imaging methods include biplane fluoroscopy,digital subtraction angiography with road mapping technology, venousangiography with road mapping technology, 3D-rotational angiography orvenography (3DRA or 3DRV), and cone-beam computed tomographicangiography or venography (CBCTA or CBCTV). Both 3DRA/V and CBCTA/Venable volumetric reconstruction showing the relationship between thebony anatomy, the venous anatomy and the radiopaque catheters andguidewires used for shunt deployment. The methods of deploying the shunt200 comprise imaging the shunt 200 while deploying the shunt 200 in thepatient.

In some embodiments, positioning the delivery catheter 304 within theIPS 102 also includes rotating the delivery catheter 304 about itscentral axis to properly orient the delivery catheter 304 prior todeploying the shunt 200 or introducing the shunt 200 into the distalportion 344 of the delivery catheter 304. As shown in FIG. 4D (describedin greater detail below), in certain embodiments, the delivery catheter304 is curved (e.g., pre-curved, biasedly curved, flexible, drivabledistal portion via control wires, or the like, or combinations thereof)near the distal portion 344 of the catheter so that when the deliveryguidewire 308 and/or the shunt 200 are advanced through the deliverycatheter 304, they approach and reach the IPS wall 114 at an anglerelative to a central axis 103 of IPS 102 (FIGS. 4B-C). The deliverycatheter 304 can be rotated, for example, by applying a rotational forcedirectly to the body of the delivery catheter 304, or to the deliveryguidewire 308 if the guide wire is connected to the delivery catheter304. Positioning the curved distal portion 344 of the delivery catheter304 in the desired orientation adjacent to the IPS wall 114 canfacilitate puncturing of the IPS wall 114 and arachnoid layer 115 toaccess the CP angle cistern 138. When deploying the shunt 200, themethods of deployment comprises introducing the shunt 200 into thepatient's body while the shunt 200 is at least partially disposed in thedelivery catheter 304, and wherein the delivery catheter 304 is advancedover guidewire extending through a lumen of the delivery catheter 304,which may be a same or different lumen in which the shunt 200 is atleast partially disposed, until a distal portion of the deliverycatheter 304 is positioned in the IPS 102 (FIG. 4B).

Referring to FIG. 4C, prior to introducing the shunt 200, a tissuepenetrating element 306 located at a distal portion 354 of an elongatepusher member 310 (e.g., piercing micro-wire) having a penetratingmember 306, can be used to pierce the IPS wall 114 and arachnoid layer115, creating anastomosis 140 (e.g., a connection channel, hole, spaceinto which the shunt 200 is later delivered and implanted). The elongatepusher member 310 may be advanced through either the guide catheter 320or delivery catheter 304. By applying a suitable mechanical force to theelongate pusher member 310, the penetrating member 306 can be advancedthrough the IPS wall dura mater 114 and the arachnoid layer 115 thatseparate the lumen of IPS 102 from subarachnoid space 116 (FIG. 2),creating the anastomosis 140 for the shunt 200 deployment. For example,the penetrating element 306 may include a needle tip with a rounded orbullet-like configuration. The penetrating element 306 rounded orbullet-like tip separates the dura fibers without damaging them whilethe elongate pusher member 310 having sufficient stiffness passesthrough the dura mater of IPS wall 114 and the arachnoid layer 115 intothe CP angle cistern 138.

Alternatively, the penetrating element 306 includes a sharpened tip ortrocar, which cuts through the IPS wall dura mater 114 and the arachnoidlayer 115 to create the anastomosis 140 for the shunt 200 deployment. Incertain embodiments, the penetrating element 306 includes a controllableradiofrequency ablation device for creating the anastomosis 140 throughthe dura mater of IPS wall 114 and the arachnoid layer 115 to access theCSF-filled space of the CP angle cistern 138.

Further, an interface between the penetrating element 306 and the shunt200 is provided to collaboratively create the anastomosis 140, whichwill be described in greater detail in FIG. 33A-C.

The location of the penetrating element 306 relative to the IPS wall 114can be monitored using any of the imaging techniques described above,and/or can be detected based on a tactile feedback communicated by theelongate pusher member 310 to a clinician. For example, a clinician candetect a brief “click” or “snap” (e.g., tactile feedback) as thepenetrating element 306 passes and creates anastomosis 140 through IPSthe wall 114. The elongate pusher member 310 and/or penetrating element306 can include one or more radio-opaque markers 356, 366 to assist invivo imaging and guidance while the clinician creates the anastomosis140 for shunt deployment. For example, suitable markers can be included(e.g., embedded) or applied (e.g., coatings) to the outer surface of thepenetrating element 306 and/or elongate pusher member 310 in a patternthat is readily/visually recognized by the clinician. An example of aradio-opaque material that can be used to apply suitable markings isbarium sulfate.

Once the IPS wall 114 and arachnoid layer 115 are pierced creating theanastomosis 140, the elongate pusher member 310 and the penetratingelement 306 are withdrawn. Next, as shown in FIG. 4D, the shunt 200 isadvanced through the delivery catheter 304 (i.e., inner lumen 305 of thedelivery catheter 304) into the anastomosis channel 140 formed bypiercing the IPS wall 114 and arachnoid layer 115. Alternatively, whenthe shunt 200′ that includes a piercing element is used in the deliveryassembly 300, the shunt 200′ pierces the IPS wall 114 and arachnoidlayer 115 creating the anastomosis; so that the distal portion 202 ofthe shunt 200′ is disposed into the anastomosis channel 140 withoutrequiring withdrawal of the piercing element, elongate pusher member 310or penetrating element 306. The alternative method using the shunt 200′having a piercing element will be described in greater detail in FIGS.5A-I and FIGS. 14F-H. As further alternatives, the shunt 200 canaccompany a penetrating element through the dura of IPS wall 114 andarachnoid 115 (e.g., as described in FIGS. 20A-F) or shunt 200 can bedelivered through a lumen of the penetrating element (e.g., as describedin connection with FIGS. 43, 44, 47), without an exchange or removal ofdelivery system components between the penetration and shunt deploymentsteps of the implant procedure.

Referring back to FIG. 4D, the shunt 200 can be delivered through thedelivery catheter 304 by advancing over the delivery guidewire 308. Thedistal portion 202 of the deployed shunt 200 comprises a distalanchoring mechanism 229, as shown, for example in FIG. 22A, thatpositions the distal portion 202 of the shunt so as to maintain the oneor more CSF intake openings 201 separated, apart and/or directed awayfrom an arachnoid layer 115 of the CP angle cistern 138. The proximalportion 204 of the deployed shunt 200 comprises a proximal anchoringmechanism 227, as shown, for example in FIG. 22A, that positions theproximal portion 204 of the shunt to thereby maintain a CSF outflow portand/or valve 209 opening disposed in the proximal portion of the shunt200 separated, apart and/or directed away from a wall of the jugularvein 106. To facilitate placement of shunt 200 using a guidewire, thebody of shunt 200 can include an interior lumen 217, separate from thelumen 215 used to communicate CSF (FIG. 8), which is dimensioned toreceive or slide over the delivery guidewire 308, or a groove or rail(e.g., on an internal surface or on the external surface of the shuntbody) that mates in complementary fashion with a correspondingstructural feature of the delivery guidewire 308. In addition to forwardadvancement of shunt 200 relative to the delivery catheter 304, aconnection interface 213 and 313 (FIG. 7) between the delivery guidewire308 and the shunt 200 permits rotation (e.g., by rotating guidewire 308)of the shunt 200 about a central axis of the shunt body 203 to ensurethat the distal portion 202 of shunt 200 is properly oriented to tracktoward a deployment site in the CP angle cistern 138.

The delivery catheter 304 disposed within the IPS 102 and, when present,the curved end distal portion 344 of the delivery catheter 304, allowsfor the distal portion 202 of the shunt 200 to be delivered into theanastomosis channel 140 and to extend into the CP angle cistern 138,while allowing the body portion 203 of shunt 200 to be disposed withinthe IPS 102, and the proximal portion 204 of the shunt 200 to extendthrough the junction 118 and into the jugular bulb 108 and/or jugularvein 106. After the shunt 200 is properly positioned, the deliverycatheter 304, and any remaining elements of the delivery assembly 300(e.g., delivery guidewire 308, guidewire 302, and guide catheter 320)are withdrawn, leaving the implanted shunt 200 in situ, as shown in FIG.3A. The implanted shunt 200 provides a fluid communication between theCP angle cistern 138 and into the jugular vein 106, so that CSF isdrained through the lumen 207 (or 215 when the shunt 200 includesmultiple lumens) of the shunt 200. The CSF within the CP angle cistern138 enters the lumen 207 opening at the distal portion 202 of the shunt200, flows through the lumen 207 at the body 203, and emerges from thelumen 207 opening at the proximal portion 204 of the shunt 200, so thatCSF is then carried away by venous circulation within jugular bulb 108and/or jugular vein 106.

As discussed above in connection with the guide catheter 320 and thedelivery catheter 304, a variety of different imaging techniques can beused to ensure proper or desirable deployment of the shunt 200 withinthe CP angle cistern 138 and IPS 102. A clinician deploying the shunt200 can also rely on tactile feedback, communicated through the deliveryguidewire 308 or the delivery catheter 304, to ensure proper positioningof the shunt 200. Typically, once properly deployed, the distal portion202 of the shunt 200 extends above arachnoid layer 115 into the CP anglecistern 138 at a distance between 1 mm to 5 mm (e.g., 2-3 mm), or anyother suitable length configured to extend into the CP angle cistern 138while leaving suitable clearance between the distal tip of the shunt 200and the brain stem 112.

In some embodiments, the shunt 200 and/or penetrating member of thedelivery system includes measurement features to confirm appropriateplacement within the CP angle cistern 138 (e.g., an electricalresistance detector configured to differentiate between dura mater andCSF, a fluid composition detector configured to differentiate betweenblood and CSF, and/or a light source and sensor configured todifferentiate between dura mater, blood, and CSF based on reflectedlight). Further, in some embodiments a stop member is proximallydisposed to the penetrating element 306 (surgical tool or any otherpiercing element) preventing the penetrating element 306 and/or theshunt 200/200′ from being deployed beyond a suitable distal length intothe CP angle cistern 138, allowing suitable clearance between the distaltip of the shunt 200/200′ and the brain stem 112, while avoidingabutting or the damaging brain stem 112. In some embodiments, a cover260 slidably disposed over the tissue penetrating member 250 of theshunt 200′ is provided to cover the tissue penetrating member 250 afterdeployment of the shunt 200′, which will be described in greater detailin FIG. 61 A-D.

Before or after deployment of the shunt 200, confirmation that theanastomosis 140 has been created between the CP angle cistern 138 andIPS 102 may be performed. For example, CSF can be withdrawn through thedelivery catheter 320 using a syringe connected to the Luer assembly 17of the delivery assembly 300 (FIG. 3B), confirming that the wall 114 andarachnoid 115 have been penetrated, the CP angle cistern 138 has beenaccessed, and/or the anastomosis 140 has been created. In someembodiments, the delivery catheter 320 includes measurement features toconfirm that the anastomosis 140 has been created with the CP anglecistern 138 (e.g., an electrical resistance detector configured todifferentiate between dura mater and CSF, a fluid composition detectorconfigured to differentiate between blood and CSF, and/or a light sourceand sensor configured to differentiate between dura mater, blood, andCSF based on reflected light).

FIGS. 4A-D disclose one exemplary method for deploying the shunt 200 totreat hydrocephalus. According to the disclosed inventions, the steps,sequence of steps, shunt, and delivery assembly 300 elements to performthe steps, can be modified in a variety of ways. For example, in analternative method, the shunt 200 is deployed without using the deliverycatheter 304. That is, the shunt 200 is detachably coupled to thedelivery guidewire 308 and advanced through the guide catheter 320 untilit is properly positioned within the CP angle cistern 138 and IPS 102.Then, the delivery guidewire 308 can be detached from the shunt 200, andthe guidewire 308 and guide catheter 320 are withdrawn, allowing theshunt 200 to remain in situ and facilitate flow of CSF from the CP anglecistern 138 into jugular bulb 108 and/or jugular vein 106.

In a further alternative method, the delivery catheter 304 can be usedto pierce IPS wall 114 creating all or a portion of the anastomosis 140.For example, the distal portion 344 of delivery catheter 304 can be cutat an angle with respect to a central axis of the catheter body, forminga sharp, tapered, cannula-like end, which will be described in greaterdetail below. By applying a suitable force to the delivery catheter 304,the distal portion 344 can be pushed through and pierce the IPS wall 114to create all or a portion of the anastomosis 140. This method can beused together with, or instead of, the use of the penetrating element306 connected to the elongate pusher member 310 to complete theconnection between the lumen of IPS 102 and CP angle cistern 138.

It should be appreciated that more than one shunt 200 can be implantedat the target site. For example, when the implanted shunt 200 does notcompletely occupy the IPS 102, a clinician may have sufficient spacewithin the IPS 102 to deploy a second shunt. The second shunt may beimplanted in the IPS 102 adjacently or proximate to the previouslyimplanted shunt 200.

FIGS. 5A-J illustrate an alternative method of delivering and implantingthe shunt 200 into the target site to drain CSF from a cerebral cistern,in accordance with embodiments of the disclosed inventions. For ease inillustration, the features, functions, and configurations of thedelivery assembly 300′ are the same as in the assembly 300 of FIGS. 4A-Dare given the same reference numerals. The delivery assembly 300′ ofFIGS. 5A-J includes the guide catheter 320, the delivery catheter 304,the delivery guidewire 308 of the assembly 300. The delivery assembly300′ further includes a detachably coupled shunt 200′ having a tissuepenetrating member 250 disposed on the distal portion 202 of the shunt200′. Alternatively, the tissue penetrating member 250 may be a cut ofthe distal portion 202 of the shunt 200′ to form an angled, sharp,cannula-like end or include a tip needle or the like. Further, thetissue penetrating member 250 may be detachably coupled to the shunt200′ so that the tissue penetrating member 250 is detached and removedfrom the shunt 200′, once the anastomosis is created and/or the shunt200′ implanted in the target site (e.g., as shown in FIGS. 5H-J).

Once the delivery catheter 304 carrying the shunt 200′ has been advancedand positioned, using any of the methods described above, adjacent orproximate to a desired point on the IPS wall 114 where the shunt 200′ isto be implanted (FIG. 5B), the guidewire 308 may be withdrawn and theshunt 200′ is advanced (FIG. 5C). The clinician may verify theorientation of the shunt 200′, confirming the orientation of the tissuepenetrating member 250 with any of the methods described above (e.g.,fluoroscopic) (FIG. 5D). The method includes positioning the distalportion 344 (e.g., pre-curved, biasedly curved, flexible, drivabledistal portion via control wires, or the like, or combinations thereof)of the delivery catheter 304 in the proper orientation relative to theIPS wall 114 (e.g., so that the open distal end of delivery catheter 304faces and/or abuts IPS wall 114) to facilitate puncturing of the IPSwall 114 and arachnoid layer 115, and access to the CP angle cistern 138(FIG. 5E). The positioning of the distal portion 344 of the deliverycatheter 304 may include adjusting the rotational orientation of thedelivery catheter 304; so that the tissue penetrating member 250 carriedon the distal portion 202′ of the shunt 200′ pierces the IPS wall 114and arachnoid layer 115 creating the anastomosis 140 at a targetpenetration site. In some embodiments, the delivery catheter 304contains a second opening spaced proximally from the distal end 344 ofthe delivery catheter 304, on an axial location of the catheter body 304(e.g., at the location of reference line 304 in FIG. 5E). The secondopening is configured to allow the delivery guidewire 308 to emerge fromthe delivery catheter 304 and extend through the IPS 102 (e.g., to theposterior aspect of the cavernous sinus) beyond the shunt 200 deploymentsite. This configuration of the delivery catheter 304 and the deliveryguidewire 308 allows the clinician to orient the delivery catheter 304about the proposed shunt 200′ deployment location in the IPS 102 andsupports the delivery and piercing assembly during penetration of theIPS wall 114 to create anastomosis 140.

By applying suitable mechanical force to the shunt 200′, tissuepenetrating member 250 and/or the delivery catheter 304, the tissuepenetrating member 250 can be advanced through the dura mater of IPSwall 114 and arachnoid layer 115 that separates the lumen of IPS 102from the subarachnoid space 116 (FIG. 2), creating the anastomosis 140(FIG. 5F). Alternatively, the delivery guidewire 308 may be advancedinto the CP angle cistern 138 (FIG. 5G). The distal portion 202′ of theshunt 200′ is further advanced into the CP angle cistern 138 (FIG. 5H);once the shunt 200′ is in the desired location, the distal portion 202′is secured against the arachnoid layer 115 and within the CP anglecistern 138 (FIG. 5I). In some embodiments, deploying the shunt 200′comprises advancing the distal portion 202′ of the shunt 200′ from theIPS 102 into the CP angle cistern 138 using the tissue penetratingmember 250. The tissue penetrating member 250 is coupled to a distal end202′ of the shunt 200, so that advancing the distal portion 202′ of theshunt 200′ from the IPS 102 into the CP angle cistern 138 comprisesadvancing the tissue penetrating member 250 and distal portion 202′ ofthe shunt 200′ through the dura mater tissue wall of the IPS 114, andthrough the arachnoid tissue layer 115, respectively, into the CP anglecistern 138. Verification of the desired position of the distal portion202′ end of the shunt 200′ may be performed with any of the methodsdescribed above.

The distal portion 202′ of the shunt 200′ may include an anchoringmechanism 225 that extends from, or is adjacent to, the distal portion202′. The anchoring mechanism 225 has a delivery configuration and adeployed configuration. In the delivery configuration, the anchoringmechanism 225 is configured to advance through the delivery assembly 300(e.g., delivery catheter 304) and pass through the anastomosis channel140. In the deployed configuration, the anchoring mechanism 225 isconfigured to secure the distal portion 202′ of the shunt 200 over thearachnoid layer 115 and/or within the CP angle cistern 138 to allowfluid communication of CSF from the CP angle cistern 138 into thejugular bulb 108 and/or jugular vein 106. The method depicted in FIG. 5Iincludes actuating the anchoring mechanism 225 into the deployedconfiguration to secure the shunt 200′ against the arachnoid layer 115and within the CP angle cistern 138. Alternatively, the anchoringmechanism 225 is biased to its deployed, expanded configuration (e.g.,by heat setting Nitinol to a malecot form) and constrained to a deliveryconfiguration to pass through delivery catheter 304 to the deploymentsite. As the anchoring mechanism 225 is advanced through the deliverycatheter 304 and the anastomosis 140 into the CP angle cistern 138 whereCSF pools, anchoring mechanism 225 resumes its biased, deployedconfiguration to anchor the shunt 200′ in the subarachnoid space 116.The method may include imaging the shunt 200′ during positioning,securing and implanting of the shunt 200′.

The distal portion 202′ of the shunt 200′ and/or the distal portion 202of the shunt 200, may include one or more openings 219 (e.g., hole,perforation, mesh, porous material, or the like, or a combinationthereof) that allow for fluid communication into the lumen 207 of theshunt 200′, so that CSF in the CP angle cistern 138 flows through theimplanted shunt 200′ into the jugular bulb 138 and/or jugular vein 106.Opening(s) 219 is placed closest the distal end of shunt 200 such that,once deployed, opening 219 is sufficiently spaced away from thearachnoid layer (e.g., 2 mm to 3 mm) to prevent arachnoid from creepinginto or otherwise occluding CSF flow into shunt lumen 207.

Alternatively, when the tissue penetrating member 250 is detachablycoupled to the shunt 200′, the tissue penetrating member 250 isdisengaged and removed from the implanted shunt 200′ (e.g., via aguidewire, elongate pusher member 310, or the like), as shown in FIG.5J, once the anastomosis has been created. In this embodiment, the lumen207 of the shunt 200′, particularly, the lumen 207 opening at the distalportion 202 of the shunt 200′ remains in fluid communication with the CPangle cistern 138 for drainage of CSF. In this embodiment, CSF entersthe shunt lumen 207 through the distal tip of shunt 200′ and openings219.

It should be appreciated that the method disclosed in FIGS. 5A-J mayinclude any steps and features disclosed herein, including steps andfeatures disclosed in connection with different embodiments, in anycombination as appropriate.

FIG. 6 shows a cross-sectional view of the shunt 200 constructed inaccordance with embodiments of the disclosed inventions. As describedabove, the shunt 200 includes proximal portion 204, distal portion 202,and elongate body 203 extending between the proximal portion 204 and thedistal portion 202. The lumen 207 extends within body 203 from aproximal end 204″ of the proximal portion 204 to distal end 202″ of thedistal portion 202, allowing CSF to pass through the body of shunt 200.The shunt 200 includes a proximal opening 205 in the proximal end 204″and/or proximal portion 204, in fluid communication with the lumen 207.The shunt 200 further includes a distal CSF intake opening 201 in thedistal end 202″ and/or distal portion 202 in fluid communication withthe lumen 207. The proximal opening 205 and the distal CSF intakeopening 201 may include one or more openings. The shunt 200 has a lengthL₂, measured along an elongate central axis 231 of the shunt 200,selected so that shunt 200 extends from the CP angle cistern 138 to thejugular bulb 108 and/or the jugular vein 106. In one embodiment, L₂ isin a range between 15 mm to 30 mm. In further embodiments, the elongatebody 203 may have variable L₂ within said range of 15 mm to 30 mm, inwhich the elongate body 203 includes expandable members, such as bellows(FIG. 6A in a compressed configuration and FIG. 6B in an expandedconfiguration), folds (FIG. 6C in a folded configuration and FIG. 6D inan unfolded/expanded configuration), slidably disposed concentrictubular elements (FIG. 6E shorter L₂ compared to larger L₂ of FIG. 6F),spring-like, coil-like (FIG. 6G more tightly wound coil—shorter L₂—thanof FIG. 6H), configurations, or the like, or combinations thereof.

In some embodiments, the distal portion 202 of the shunt 202 is expandedor self-expands from a collapsed delivery configuration to an expandeddeployed configuration as, or after, it is advanced into the CP anglecistern 138.

The shunt lumen 207 has an inner diameter L₁ measured in a directionorthogonal to axis 231 depicted in FIG. 6. The diameter L₁ can rangebetween 0.1 mm (0.004 inches) to 5 mm (0.2 inches) in differentembodiments, and preferably falls within the range of about 0.2 mm(0.008 inches) to about 0.36 mm (0.014 inches). Further, L₁ and/or L₂may have any suitable dimension for implantation of the shunt 200 in thetarget site (e.g., IPS, CP angle cistern, or the like).

In some embodiments of the inventions, a constriction in the innerdiameter L₁ of shunt lumen 207 for a particular length L₂ is calculatedbased on the Hagen-Poiseuille equation to enable shunt 200 to providefor a target flow rate of CSF (in a range of about 5 ml per hour toabout 15 ml per hour) through the shunt 200 at a normal differentialpressure, defined as being in a range between about 5 cm H2O to about 12cm H2O between the subarachnoid space 116 and venous system, as:

${\Delta \; P} = \frac{128\mspace{14mu} \mu \mspace{14mu} L\mspace{14mu} Q}{\frac{\pi \mspace{14mu} d^{4}}{\begin{matrix}{\mu \text{:}\mspace{14mu} {viscosity}} \\{Q\text{:}\mspace{14mu} {flow}\mspace{14mu} {rate}} \\{\Delta \; P\text{:}\mspace{14mu} {differential}\mspace{14mu} {pressure}} \\{L\text{:}\mspace{14mu} {length}} \\{d\text{:}\mspace{14mu} {diameter}}\end{matrix}}}$

For example, constricting the inner diameter L₁ of shunt lumen 207 to0.19 mm over a length L₂ of 8 mm will maintain a CSF flow rate of 10mL/hour at a differential pressure of 6.6 cm H20. In the shuntembodiments without a constriction in the inner lumen, the same equationand approach can be used to configure the inner diameter of the shuntlumen along the entire length of the shunt body 203 to achieve a targetflow rate (or range) for a given differential pressure (or range).

In some embodiments, the shunt 200 may include one or more valves toregulate the rate of CSF flow within the shunt 200, while allowing flowof CSF only in one direction, i.e., from the distal portion 202 to theproximal portion 204 of the shunt 200. FIG. 6 depicts a valve 209disposed within the shunt body 203, in fluid communication with thelumen 207 of the shunt 200. The valve 209 may be disposed at anysuitable location within the body 203, for example, proximate to or atthe proximal portion 204, to the distal portion 202, and/or in betweensaid portions 202, 204. In certain embodiments, multiple valves can bedisposed at different locations within the shunt 200.

Valve 209 can include a specific cracking pressure that, when met orexceeded by the positive pressure gradient between the subarachnoidspace and venous system, opens the valve thereby facilitating CSF flowfrom the CP angle cistern into the jugular vein. For example, thecracking pressure of valve 209 can be configured from about 3 mm Hg toabout 5 mm Hg and/or when the differential pressure between thesubarachnoid space and venous system reaches from about 3 mm Hg to about5 mm Hg; however, other cracking pressures can be configured in valve209 depending on the particular clinical needs of the patient.

The valve 209 may have a variety of suitable features. For example, thevalve 209 is a one-way valve, such as a duck-bill valve, as shown inFIG. 6 and FIG. 6I. Other suitable valves 209 can be used in the shunt200, such as umbrella valves, pinwheel valves, ball and spring valves(FIGS. 6J-K), concentric tube valves (FIG. 6L), slit valves, checkvalves, flapper valves (FIG. 6N-O) or the like, or combinations thereof.In addition, a one-way valve can be formed from electrolyticallyerodible materials that can be selectively eroded to configure the flowrate through the valve by applying current to the valve for a specificperiod of time. Suitable materials, systems, and methods that can beused to configure such an erodible valve are further described in U.S.Pat. No. 5,976,131, the entire content of which is incorporated hereinby reference.

FIGS. 6P-6T illustrate the valve 209 constructed according to oneembodiment of the disclosed inventions. As shown in FIG. 6P, the valve209 comprises a molded silicone element configured to fit over theproximal portion 204 of the shunt 200. The proximal portion 204 of theshunt 200 has a narrowed outer diameter L₄ (e.g., dotted line portion ofFIG. 6P) relative to the outer diameter L₃ of the body 203 of the shunt200, configured to support the valve 209 over the proximal portion 204(FIG. 6R). The proximal portion 204 of shunt 200 includes a beveled edgethat terminates at a proximal end 204″ (e.g., tip) of the shunt 200(FIGS. 6Q-T). As shown in FIG. 6R, the valve 209 includes a protrusion239 extending from an inner surface 299 of the valve 209. The protrusion239 is dimensioned and configured to engage a recess 238 formed in theouter surface 206 of the proximal portion 204 of the shunt 200. When thevalve 209 is inserted over the proximal portion 204 of the shunt 200,the protrusion 239 and recess 238 engage, thereby securing the valve 209over the proximal portion 204 of the shunt 200. The valve 209 caninclude two or more interlocking protrusions 239, spaced apart (e.g., oron opposing sides of the valve 209 inner surface 299—FIG. 6R), and theshunt 200 includes corresponding recesses 238 in the outer surface 206configured to engage the respective protrusions 239 of the valve 209.The valve 209 further includes a first portion 249 having a closedconfiguration, in which the portion 249 seats and/or covers the bevelededge and the proximal opening 205 of the shunt 200 in communication withthe lumen 207 stopping fluid flow out of the lumen 207 (FIGS. 6P-R), andhaving an opened configuration in which the portion 249 separates fromthe beveled edge and the proximal opening 205 of the shunt 200 incommunication with the lumen 207 in a swing motion or hinged-likefashion, allowing fluid flow out of the lumen 207 (FIG. 6S). The valve209 includes a second portion 259 configured to cover a portion of theouter surface 206 of the shunt 200, as shown in FIGS. 6R-T. The first249 and second 259 portions of the valve 209 may be formed by creating acut or slit 269 in the molded silicone element of the valve 209.

When the shunt 200 having the valve 209 of FIGS. 6P-T is implanted atthe target site in a patient, as previously described, the first portion249 can open from the closed configuration (FIGS. 6P-R) to the openedconfiguration (FIG. 6S) under positive differential pressure conditionsbetween the subarachnoid space 116 (e.g., CP angle cistern 138) and thevenous system (e.g., jugular vein 106). A relatively large surface areaof first portion 249 provides a substantial swing motion when openingthe valve 209 to facilitate clearing of any aggregated materials insideshunt 200 (e.g., CSF proteins, arachnoid layer cells), and canaccommodate a wide range of flow rates with relatively low opening orcracking pressure (e.g., about 3 mm Hg to about 5 mm Hg). The firstportion 249 can also open to receive the guidewire 308, as shown in FIG.6T to assist with the navigation and deployment of the shunt 200, asdescribed herein. Under negative differential pressure conditions (e.g.,where venous blood pressure exceeds intracranial pressure insubarachnoid space 116, such as during sneezing or coughing events), thefirst portion 249 closes to seal, shut and/or close the valve 209 (FIG.6R) preventing venous blood from flowing back through the shunt 200 intothe subarachnoid space 116. The large surface area of the first portion249 provides a substantial area for negative pressure (−P) to compressagainst and seal the valve 209 closed to prevent backflow of materialthrough shunt 200 (FIG. 6R).

In addition to controlling flow of CSF from the subarachnoid space tothe venous system, shunt 200 preferably prevents backflow of blood fromthe jugular bulb 108 and vein 106 through shunt lumen 207 into thesubarachnoid space 116. Having one-way valves in the shunt 200 areparticularly advantageous, as they allow CSF to be in fluidcommunication from the CP angle cistern 138 into the venous circulatorysystem (e.g., the jugular bulb 108, jugular vein 106), while preventingbackflow of venous blood into the subarachnoid space 116 (e.g., CP anglecistern 138).

In some embodiments, the one or more valves in the shunt 200 can bedetachable from the shunt 200. For example, referring to FIG. 6, thevalve 209 includes an attachment mechanism 211 that connects the valve209 to the body 203 of the shunt 200. The valve 209 can be detached andremoved from the shunt 200, even when the shunt 200 is implanted, byactivating the mechanism 211 (e.g., by actuating the mechanism 211 usinga guide wire inserted into shunt 200). In some embodiments, the shunt200 includes a plurality of different valves 209, where each valveallows for a different rate of fluid flow. A clinician can control therate at which CSF drains from the CP angle cistern 138 into the jugularbulb 108 and/or the jugular vein 106, for example, by selectivelyconnecting one or more suitable valves to the shunt 200.

The valve 209 (or a combination of valves), and/or another type of flowregulating device (e.g., constriction of the inner diameter of shunt 200for a particular length as previously described, compressed shunt body203 narrowing lumen 207, FIG. 6M), is configured to achieve a desiredrate of flow of CSF from the CP angle cistern 138 into the jugular bulb108 and/or the jugular vein 106. For example, duckbill, slit, andwindsock valve configurations typically cannot regulate flow based onvalve cracking pressure alone; once opened, such valves continuouslyseep fluid and therefore, can be combined with a constriction of theinner diameter of shunt 200 for a particular length as previouslydescribed to further regulate CSF flow. A desired rate of flow is in arange between 5 ml per hour to 20 ml per hour and more desirable between10 ml per hour to 18 ml per hour. In some embodiments, the desired flowrate of CSF is approximately 10 ml per hour. In a 24-hour period, theflow of CSF through shunt 200 can be between 200 ml to 300 ml (e.g.,200, 225, 250, 275, or 300 cm³).

In some embodiments, the shunt 200 can include an anti-thromboticcoating to prevent thrombosis induced by the deployment of the shunt200. For example, the shunt 200 may include an anti-thrombotic coating221 disposed along the length of the shunt body 203. Anti-thromboticcoating 221 can generally be applied to any one or more of the innersurfaces and/or outer surface of the shunt 200. In addition, theanti-thrombotic coating 221 can be applied along the entire length ofshunt 200, or alternatively, only on selected portions of the innerand/or outer surfaces of shunt 200 (e.g., in the proximate to or in thevicinity of the end(s) of shunt 200). Suitable materials that can beused to form anti-thrombotic coating 221 include, for example, Parylene,polytetrafluoroethylene derivatives, and Heparin.

The shunt 200 is composed of biocompatible materials. Suitable materialsinclude, for example, platinum, Nitinol®, gold, or other biocompatiblemetal and/or polymeric materials, for example, silicon, or combinationsthereof. In some embodiments, the shunt 200 may include materials thatare compatible with magnetic resonance imaging and have radiopacitysufficient to allow imaging with the use of the various techniquesdisclosed above. For example, one or more markings formed of aradio-opaque material may be applied to the surfaces of shunt 200 toassist in vivo imaging of the shunt 200 during delivery and deployment(i.e., implantation in target site). Suitable markers may be included(e.g., embedded) or applied (e.g., coatings) to the outer surface 206 ofthe shunt 200 in a pattern that is readily recognized by a clinician. Anexample of radio-opaque materials that can be applied for markings isbarium sulfate. Such markers can also be applied to the catheters and/orguidewires used during a shunting procedure to assist in vivo imaging ofthe various system components during shunt 200 delivery and deployment.

In some embodiments, portions of the shunt 200 may be composed offlexible materials, or the shunt 200 may have portions of variousdegrees of flexibility. For example, the distal portion 202 is composedof a flexible material so that the distal portion 202 is more flexiblethan the body 203 of the shunt 200 (FIG. 6). Suitable materials maycompose the distal portion 202 of shunt 200, which may include flexible,elastomeric materials such as silicone or Nitinol (e.g., Nitinolhypotube with a reduced wall thickness or an ePTFE-lined Nitinolhypotube with a latticed or relief cut configuration to increaseflexibility for navigating tortuous anatomy). The flexible shunt 200,particularly the flexible distal portion 202, facilitates bending of theshunt 200 within delivery catheter 304, so that the shunt 200 createsand/or accesses the anastomosis channel 140 into the CP angle cistern138 at a suitable angle relative to the IPS 102 (e.g., FIG. 4D).Referring back to FIG. 6, the distal portion 202 composed of flexiblematerials allows for bending of the portion 202 in an axis 233, so thatthe distal portion 202 is configured to access the CP angle cistern 138via the anastomosis channel 140, at an angle “A”. The distal portion 202of the shunt 200 may be pre-curved, biasedly curved, flexible, bendablevia control wires or the like or combinations thereof, in an angle withrespect to the body 203 axis 231 to form a suitable angle relative tothe central axis 103 of the IPS 102 for penetration and/or implantationof the shunt 200 through the anastomosis channel 140. The angle “A” maybe in a range of 5 degrees to 80 degrees between axes 231 and 233.

In some embodiments, the distal portion 202 of the shunt 200 can be cutin an angle to form a piercing element (e.g., sharp, tapered,cannula-like end, or bevel, pencil, or Quincke tip) allowing piercingthe IPS wall 114 and the arachnoid layer 115. As shown in FIG. 6, theangle “C” of the distal portion 202 with respect to axis 233 can beselected as desired for a particular “sharpness” of the piercingelement. In some embodiments, angle “C” is between 5 degrees to 80degrees with respect to axis 233.

The shunt 200 can include one or more anchoring mechanisms 225positioned along the body 203 of shunt 200, as shown in FIG. 6. Theanchoring mechanisms 225 allow the implanted shunt 200 to be secured inthe target site, and allow the shunt 200 to remain in the implantedlocation (e.g., FIG. 3A). The anchoring mechanisms 225 can include oneor more configurations, such as, hooks, barbs, expandable arms,petal-like, coil-like, malecot, elliptecot, T-bar features, or the like,or combinations thereof. The anchoring mechanisms 225 can be disposed inone or more portions of the shunt 200. The anchoring mechanisms 225include a delivery configuration in which the mechanism 225 is radiallyconstrained, and a deployed configuration in which the mechanism 225 isradially expanded. The anchoring mechanisms 225 may includeself-expanding features so that the mechanism radially expands when theshunt 200 is deployed out of the delivery catheter 304 and/or guidecatheter 320. Additionally or alternatively, the anchoring mechanisms225 may be selectively actuated into the deployed configuration, forexample, with the use of a guidewire (e.g., guidewire 302, deliveryguidewire 308) inserted into the shunt 200.

In some embodiments, the shunt 200 may include one or more anchoringmechanisms 225 disposed at the distal portion 202 of the shunt 200,which secures the implanted shunt 200 in situ at the IPS 102, andparticularly securing the distal portion 202 within CP angle cistern138. In some embodiments, the shunt 200 may further include one or moreanchoring mechanisms 225 disposed at the proximal portion 204 of theshunt 200, which secures the implanted shunt 200 in situ at the IPS 102,and particularly securing the proximal portion 204 within the junction118, jugular bulb 108 and/or jugular vein 106. The anchoring mechanism225 can be collapsible to allow for shunt retrieval and/or replacement.It will be appreciated that combinations of different anchoringmechanisms may be used in the proximal portion 204 and/or the distalportion 202 of the shunt 200.

In some embodiments, the shunt 200 can include one or more features thatallow for accurate guidance, navigation and/or control of the shunt 200,particularly when passing the shunt 200 from the jugular bulb 108 orjugular vein 106 through the junction 118 into the IPS 102, and/or intothe anastomosis channel 140. FIG. 7 illustrates a cross-sectional viewthe shunt 200, according to one embodiment of the disclosed inventions.The shunt 200 includes a protruding rib 213 extending along an outersurface 206 of the shunt 200. The rib 213 is dimensioned and configuredto engage a cooperating recess 313 in the delivery catheter 304. Therecess 313 is formed within an inner surface 316 of the deliverycatheter 304. When the shunt 200 is inserted into the delivery catheter304, the rib 213 and recess 313 slidably engage, allowing the shunt 200to be guided in a desired orientation within delivery catheter 304. Theembodiment shown in FIG. 7 is an exemplary control feature that can beimplemented in connection with the shunt 200. In some embodiments, theshunt 200 and the delivery catheter 304 can include a plurality of suchfeatures (e.g., a plurality of ribs that engage with a plurality ofrecesses). Although the shunt 200 includes a rib 213 in FIG. 7, in analternative embodiment, the delivery catheter 304 can include a rib, andthe shunt 200 may include a recess dimensioned and configured toslidably engage with the delivery catheter 304.

Additionally or alternatively, the guide catheter 320 can includefeatures that engage with the control features of shunt 200 (e.g., oneor more rails or recesses) and/or delivery catheter 304. For example,the delivery catheter 304 and the guide catheter 320 can each includeone or more features that engage with the control features of shunt 200.Further, the delivery catheter 304 and the guide catheter 320 caninclude control features (e.g., one or more ribs or recesses) thatcooperatively engage, allowing the catheters 304, 320 to move relativeto one another in a controlled orientation. Cooperatively engagingfeatures can also be employed between the delivery guidewire 308 and thedelivery catheter 304, and between the elongate pusher member 310 andthe delivery catheter 304 and/or the guide catheter 320. Examples ofsuch features include any of the features discussed above in connectionwith shunt 200 and delivery catheter 304.

FIG. 8 illustrates a cross-sectional view of the shunt 200 having afirst lumen 215 and a second lumen 217 constructed in accordance withembodiments of the disclosed inventions. The first lumen 215 isconfigured to allow flow of CSF from the CP angle cistern 138 into thejugular bulb 139 and/or the jugular vein 106, as discussed above. Thesecond lumen 217 is configured to allow a guidewire (e.g., guide wire302, delivery guide wire 308, elongate pusher member 310, tissuepenetrating member 250, tissue penetrating member 250, actuatingguidewire or the like) to be inserted and slidably disposed into, andthrough, the shunt 200. The guidewire can be used by a clinician toassist with navigation and deployment of the shunt 200 in a target site.Further, the clinician can use the guidewire within the second lumen 217to access shunt components (e.g., valves, anchoring mechanisms). In someembodiments, the clinician can use a penetrating element (e.g., tissuepenetrating member 306, 250, 350) attached to a guidewire that passesthrough the second lumen 217 to pierce the IPS wall 114 and access theCP angle cistern 138. Additionally, the clinician can confirm that CSFflow path between the CP angle cistern 138 and the jugular bulb 108and/or the jugular vein 106 remains open, and/or dislodge any occlusionsin either of the lumens 215 and/or 217. In some embodiments, CSF can bewithdrawn by the clinician through either lumen 215 or 217 of the shunt200, confirming that the IPS wall 114 has been penetrated, the CP anglecistern 138 accessed, and the anastomosis 140 has been created. In otherembodiments, the shunt 200 may include a plurality of lumens, forexample, more than the two lumens 215 and 217.

Additionally, the cross-sectional configuration of the shunt 200 may beof any suitable configuration for shunt implantation in the IPS 102. Forexample, the cross-sectional configuration of the shunt 200 may have acircular (FIG. 8), non-circular (e.g., elliptical), or any other regularor irregular configuration. FIG. 9 illustrates an ellipticalcross-sectional configuration of the shunt 200, according to theembodiments of the disclosed inventions. The elliptical cross-sectionalconfiguration of the shunt 200 may be a better support for a sharp,tapered, cannula-like end of the distal portion 202 of the shunt 200than a circular cross-sectional configuration.

FIG. 10 illustrates the delivery catheter 304 constructed according toembodiments of the disclosed inventions. The catheter 304 includes anelongate body 345 that extends along an elongate axis 331. The deliverycatheter 304 includes a proximal portion 342, an elongate body 345, adistal portion 344, and a lumen 341 extending therebetween. The deliverycatheter 304 includes a proximal opening 348 in the proximal portion 342in fluid communication with the lumen 341. The delivery catheter 304further includes a distal opening 346 in the distal portion 344 in fluidcommunication with the lumen 341. The distal portion 344 of catheter 304is curved (e.g., pre-curved, biasedly curved, flexible, drivable distalportion via control wires or the like or combinations thereof) relativeto the catheter body 345 and/or axis 331. The distal portion 344 allowsfor bending in an axis 333, so that the distal portion 344 is configuredto access the CP angle cistern 138 via the anastomosis channel 140created during shunt deployment, at an angle “B” for deployment of theshunt 200. The angle “B” may be in a range of 5 degrees to 80 degreesbetween axes 331 and 333.

In accordance with the disclosed inventions, the distal portions 202,324, 344 of either of the shunt 200, guide catheter 320 and/or deliverycatheter 304 are configured to curve and/or bend. Exemplary variationsof some of the largest and smallest straight angles, as well as some thelargest and smallest bend angles, for an IPS 102 having a diameterranging from 2 mm to 4 mm are shown in FIGS. 11A-C. Such angles can alsobe used to assess whether delivery system assembly 300 and penetratingelement 250 or 350 configurations disclosed herein can achieve a desiredpenetration angle into IPS wall 114 for a given IPS diameter. It shouldbe appreciated that the angle variations depicted in FIGS. 11A-C areexemplary and not intended to limit the embodiment of FIGS. 11A-C.

FIG. 12 illustrates one embodiment of the shunt 200, constructed inaccordance with the disclosed inventions. The shunt 200 includes aplurality of anchoring mechanisms 225. An anchoring mechanism 227 mayextend from and/or be disposed on the proximal portion 204 of the shunt200, and an anchoring mechanism 229 may extend from and/or be disposedon the distal portion 202 of the shunt 200. The anchoring mechanism 227has a delivery configuration and a deployed configuration, as describedabove for the anchoring mechanism 225. Alternatively or additionally,the anchoring mechanism 227 and 229 may be disposed on a conduit 400(e.g., collapsible barbs 425 depicted in FIG. 12).

The anchoring mechanism 227 may include any suitable anchoringconfiguration, such as, a spring-loaded plug, stent, mesh, malecot, orthe like, coupled to the proximal portion 202. The anchoring mechanism227 may be composed of a shape-memory material such as Nitinol®,expandable material, such as swellable polymeric foams, or the like orcombinations thereof. The anchoring mechanism 227 is configured toengage the junction 118 where the IPS 102 enters the jugular bulb 108and/or jugular vein 106, and/or is configured to engaged the jugularbulb 108 or jugular vein 106, securing and preventing movement of theshunt 200 when implanted, particularly, securing the proximal portion204 of the shunt 200 in situ. For example, prior to deployment of theshunt 200, the anchoring mechanism 227 is radially constrained allowingpassage of the shunt 200 through the junction 118 in the IPS 102. Oncethe shunt 200 is deployed, the anchoring mechanism 227 radially expandswithin the junction 118 (e.g., self-expansion, swelling due toabsorption of fluid and/or increased temperature) to anchor shunt 200 atthe proximal portion 204 as shown in FIG. 12. Additional embodiments ofthe anchoring mechanism 227 will be described in further detail below.

The anchoring mechanism 229 that extends from the distal portion 202 ofthe shunt 200 is configured to engage the arachnoid layer 115 and/or theexterior portion of the IPS wall 114 when the shunt 200 is implanted inthe target site (e.g., IPS 102, anastomosis channel 140, CP anglecistern 138). The anchoring mechanism 229 has a delivery configurationand a deployed configuration, as described above for the anchoringmechanism 227. The anchoring mechanism 229 may include any suitableanchoring configuration. For example, the anchoring mechanism 229includes an umbrella-type configuration having a plurality of wiresaligned approximately along the axis of shunt 200. Once the shunt 200accesses the CP angle cistern 138, the anchoring mechanism 229 isactuated, so that the mechanism 229 radially expands securing the distalportion 202 of the shunt 200 in situ. Mechanism 229 advantageouslycompresses or pins down the arachnoid layer 115, around the penetrationsite in the subarachnoid space 116, against the dura mater comprisingthe exterior portion of IPS wall 114, to prevent occlusion of the shuntlumen 207 (e.g., by arachnoid mater). In some embodiments, the anchoringmechanism 229 may be actuated using a guidewire inserted into shunt 200and coupled to the mechanism 229, so that retracting the guidewireforces the mechanism wires in an outward radial direction from the axisof shunt 200, thereby anchoring the shunt 200. Alternatively, theanchoring mechanism 229 can be a collapsible, self-expandingumbrella-type mechanism that remains radially constrained while in thedelivery catheter 304 and/or guide catheter 320, and radially expandsupon deployment from such catheters into the CP angle cistern 138. Insome embodiments, the anchoring mechanism 229 may include aself-expanding circular basket with multiple collapsible tines and/or amulti-filament globe-like.

The anchoring mechanism 229 forms an anchor by having a diameter, in thedeployed configuration (e.g., 3 mm to 5 mm), larger than the diameter ofthe anastomosis channel 140. Therefore, the deployed anchoring mechanism229 is sufficiently wide to avoid passage through the anastomosischannel 140, thereby securing the shunt 200 within CP angle cistern 138.Additionally, the anchoring mechanism 229 is configured to form a sealat the anastomosis channel 140 preventing flow of blood into the CPangle cistern 138. The seal formed by the anchoring mechanism 229further prevents occlusion or clogging of the shunt lumen 207 at thedistal portion 202 by avoiding the access of blood into the CP anglecistern 138 from the IPS 102.

In some embodiments, the anchoring mechanism 227 and 229 can becollapsible to facilitate shunt retrieval and/or replacement. Additionalaspects and features of suitable anchoring mechanisms for use with shunt200 are disclosed, for example, in U.S. Patent Application PublicationNo. 2015/0196741 and published PCT Application WO2015/108917, both filedon Jan. 14, 2015, the entire contents of all of which are incorporatedby reference. It will be appreciated that combinations of differentanchoring mechanisms may be used in the proximal portion 204 and/or thedistal portion 202 of the shunt 200/200′.

In some embodiments, a conduit 400 can be used to house the shunt 200when deployed within the IPS 102 (FIG. 12). The conduit 400 is composedof a biocompatible material configured to be disposed within the IPS 102prior to the deployment of the shunt 200 (FIGS. 14A-F). The shunt 200 isconfigured for deployment within the conduit 400. The conduit 400includes a tubular configuration having a proximal portion 404, a distalportion 402 and a lumen 407 extending therebetween. The deployed conduit400 extends proximally from a target penetration site in IPS wall 114 orfrom within the CP angle cistern 138 adjacent through IPS 102 into thejugular bulb 108 and/or jugular vein 106. The conduit 400 may includeone or more anchoring mechanisms 425 that secure the conduit 400 withinthe IPS 102. The anchoring mechanisms 425 may have any suitableconfiguration, for example, hooks, barbs or the like that engage the IPSwall 114 when the conduit 400 is deployed. The distal portion 402 ofconduit 400 may be curved in a manner similar to the distal portion 202of shunt 200 and/or delivery catheter 304 to facilitate entry of shunt200 into CP angle cistern 138 at a desired angle. The conduit 400 iscomposed of a suitable expanding material, such as, biocompatiblepolymeric material that expands when heated (i.e., upon deployment intoIPS 102).

The conduit 400 may include an expandable stent-graft configuration.FIGS. 13A-C are expandable stent-grafts known in the art that may beused to construct the conduit 400. FIG. 13A illustrates a stent-graft ina collapsed state, FIG. 13B in a partially-expanded state, and FIG. 13Cin an expanded state. Further, the conduit 400 may include aself-expandable or collapsible metal stent or metal mesh-like scaffoldthat supports a biocompatible heat expandable fabric covering thescaffold.

FIGS. 14A-H illustrate an exemplary method of delivering the shunt 200′within the conduit 400 according embodiments of the disclosedinventions. Although, the shunt 200′ incorporating a piercing element isused to describe the method of deployment in FIGS. 14A-H, it should beappreciated that any configuration of the shunt 200 may be used in thismethod of deployment. The conduit 400 is deployed through a catheter(e.g., delivery catheter 304) in a radially constricted configuration(FIG. 14A). The conduit 400 radially expands within the IPS 102, forexample, after withdrawal of the delivery catheter 304 if the conduit400 is self-expanding, or by heating the conduit 400, or the like, orcombination thereof (FIG. 14B). The expanded and implanted conduit 400within the IPS 102 is shown in FIG. 14C. FIG. 14D is an insert of FIG.14C and illustrates a further detail of the curved distal portion 402 ofthe conduit 400, which facilitates guidance of shunt 200′ into CP anglecistern 138 through the IPS wall 114 and arachnoid layer 115 to createthe anastomosis channel 140. In FIG. 14E, the shunt 200′ is advancedthrough the delivery catheter 304 into the conduit 400 implanted in theIPS 102. The navigation and advancement of the shunt 200′ may beassisted by the use of a guidewire, as previously disclosed. As shown inFIG. 14F, when the shunt 200′ reaches the curved the distal portion 402of conduit 400, the distal portion 202 of the shunt 200′ bends to followthe curved profile of the conduit 400. As the shunt 200′ is advancedwithin the conduit 400, the shunt 200′ is directed toward the IPS wall114. Once the shunt 200′ reaches the IPS wall 114, a clinician appliessuitable force to the shunt 200′ (e.g. via a guidewire coupled to theshunt 200′) and the tissue penetrating member 250, incorporated in theshunt 200, penetrates and pierces the IPS wall 114 creating theanastomosis channel 140, so that the distal portion 202 of shunt 200′accesses the CP angle cistern 138 (FIG. 14G). The creation of theanastomosis 140 is also described above in FIGS. 5E-G. The shunt 200′includes the anchoring mechanism 229; in particular, the anchoringmechanism shown in FIGS. 14G-H is the distal portion anchoring mechanism229, which includes a plurality of deformable elements 229 a (e.g.,arms) and a mesh 229 b. The deformable elements/arms 229 are expandablemembers that may include any suitable configuration to allow outward,radial expansion, such as members composed of bendable or deformablematerials (e.g. Nitinol®). The mesh 229 b allows for fluid communicationinto the lumen 207 of the shunt 200′ so that CSF in the CP angle cistern138 flows through the implanted shunt 200′ into the jugular bulb 108and/or jugular vein 106. The mesh 229 b functions as the distal opening219 of the shunt 200′, as shown in FIG. 5I, and may comprise any othersuitable configurations (e.g. perforations, porous material or thelike). The arms 229 a are coupled to the tissue penetrating member 250,so that when a retrograde force 229 c is applied (e.g. via a guidewire),the tissue penetrating member 250 retracts causing the arms 229 a tobend, expand or deform in a radially outward direction 229 d, as shownin FIG. 14H, anchoring the distal portion 202 of shunt 200′ within CPangle cistern 138.

Alternatively, the arms 229 a are detachably coupled to the tissuepenetrating member 250, so that the tissue penetrating member 250 may bedetached and removed from the implanted shunt 200′, as shown in FIG. 5J.

FIGS. 15A-D illustrate detailed cross-sectional views of an alternativeembodiment of the anchoring mechanism 229 and, an exemplary method ofdelivering the shunt 200 at the target site according embodiments of thedisclosed inventions. As shown in FIG. 15A, the anchoring mechanism 229includes an inner sheath 229 f, a deformable element 229 e, and an outersheath 229 g slidably disposed over the inner sheath 229 f and element229 e. The deformable element 229 e (e.g., arms, wires, loops, layer, orthe like) includes a radially constrained delivery configuration (e.g.,outer sheath 229 g disposed over element 229 e, as shown in FIGS.15A-B), and a radially expanded deployed configuration (e.g., withdrawnouter sheath 229 g as shown in FIG. 15D). The deformable element 229 eare composed of shape memory material, e.g., Nitinol®, of any suitablebiocompatible metal, alloys, polymeric materials or combinationsthereof. The elements 229 e are coupled to the inner sheath 229 f, forexample, by adhesive, thermal bonding, welding or the like, orcombinations thereof, or by any other suitable methods. The deployedconfiguration of the deformable element 229 e is configured to expand,anchor and secure the distal portion 202 of the shunt 200 at the IPSwall 114 within the CP angle cistern 138. The tissue penetrating member250, disposed within the anchoring mechanism 229, is detachably coupledto the anchoring mechanism 229 and/or the shunt 200, so that the tissuepenetrating member 250 is detached and removed when the shunt 200 isdelivered and implanted at the target site.

After the tissue penetrating member 250 has created the anastomosischannel 140 in the IPS wall 114, the distal portion 202 of the shunt200, including the anchoring mechanism 229, is advanced by applyingsuitable force in a distal direction (indicated by the arrow in the topleft portion FIG. 15B). Portions of the inner sheath 229 f and the outersheath 229 g extend into the CP angle cistern 138 via the anastomosischannel 140. Once inside the CP angle cistern 138, the tissuepenetrating member 250 is detached and withdrawn from the shunt 200 byapplying suitable force in a proximal direction (indicated by the arrowin the top right portion of FIG. 15B). The outer sheath 229 g is alsowithdrawn, therefore exposing the deformable element 229 e in thedeployed configuration, and further exposing the inner sheath 229 f thatdefines the lumen 207 of shunt 200, as shown in FIG. 15B. The deformableelement 229 e, shown in FIGS. 15C-D, includes a plurality of Nitinol®wires that radially expand in the deployed configuration, and areconfigured to anchor and secure the shunt 200 distal portion 202 againstarachnoid layer 115 and/or the exterior of IPS wall 114 (i.e., duramater), and within CP angle cistern 138.

FIG. 16 illustrates a side view of an alternative distal anchoringmechanism 229 in accordance to embodiments of the disclosed inventions.The anchoring mechanism 229 includes a body 251 (e.g., pre-curved,biasedly curved, flexible, drivable distal portion via control wires, orthe like, or combinations thereof) composed of shape memory materials(e.g., Nitinol®) or other deformable materials, or combinations thereof.The anchoring mechanism 229 comprises a delivery configuration (e.g.,elongated for advancement through the delivery assembly 300 and/orconduit 400) and a deployed configuration (e.g., curved or arc between180 degrees to 340 degrees). The anchoring mechanism 229 furtherincludes an angled tissue penetrating member 250 configured tofacilitate the piercing of the IPS wall 114 and arachnoid layer at afirst point of entry from within the lumen of IPS 102 into the CP anglecistern 138, creating a first anastomosis channel 140 a, and at a secondpoint of entry from the CP angle cistern 138 returning into the lumen ofIPS 102, creating a second anastomosis channel 140 b. Particularly,after the first anastomosis channel 140 a is created and as the body 251curves and further advances, the tissue penetrating member 250 onceagain contacts and pierces the IPS wall 114 at the second point of entrycreating the second anastomosis 140 b. Therefore, the distal portion 202of the shunt 200 is anchored and secured in situ by having portions ofthe body 251 of the anchoring mechanism 229 disposed through bothanastomosis channels 140 a and 140 b, preventing dislodging of theimplanted shunt 200.

The body 251 of the anchoring mechanism 229 includes openings 253 (i.e.,holes, porous, perforations, or the like, or combinations thereof),allowing fluid communication into the lumen 207 of the shunt 200, sothat CSF disposed in the CP angle cistern 138 is drained when the shunt200 is implanted, according to the embodiments of the disclosedinventions. The openings 253 are formed in the body 251 of the anchoringmechanism 229 configured to be disposed within the CP angle cistern 138when the shunt 200 is implanted. It should be appreciated that portionsof the body 251 of the anchoring mechanism 229 that are configured to bedisposed within the IPS wall 114 at the anastomosis channels 140 a and140 b and/or within the IPS 102 (e.g., distal and proximal portions theanchoring mechanism 229), do not include any openings 253, so that bloodflow through the shunt 200 is prevented or avoided. The size andposition of the openings 253 can be selected to alter the physicalproperties of the body 251, for example, varying the extent of thecurvature, and the stiffness of the body 251 of the anchoring mechanism229.

FIGS. 17A-B, 18A-B, and 19A-B describe exemplary embodiments of thedistal portion 202 of the shunt 200′ having the tissue penetratingmember 250, configured to achieve a suitable angle for piercing the IPSwall 114 and the arachnoid layer 115 for implantation of the shunt 200′and creating the anastomosis channel 140 into CP angle cistern 138. Itshould be appreciated that the aspects and features of the embodimentsdescribed in FIGS. 17A-B, 18A-B, and 19A-B can be incorporated into thedistal portion 202 of the shunt 200, the distal portion 344 of thedelivery catheter 304, the distal portion 324 of the guide catheter 320,the distal portions of the guidewires (308, 304, 310) and/or any otherelement of the delivery assembly 300 configured to be disposed in theproper angle and orientation relative to the IPS wall 114 forpenetration and/or implantation, according to the disclosed embodiments.

FIGS. 17A-B illustrates an exemplary distal portion 202 of the shunt200′ according to the embodiments of the disclosed inventions. Thedistal portion 202 of the shunt 200′ is composed of shape-memorymaterials, such as super-elastic nickel titanium alloy, known asNitinol® or other suitable deformable material, so that the distalportion 202 has a pre-curved or biasedly curved configuration (FIG.17B). The distal portion 202 of the shunt 200′ comprises a deliveryconfiguration, in which the distal portion 202 is elongated foradvancement through the delivery catheter 304 (FIG. 17A) or the deliveryassembly 300 and/or conduit 400, and a deployed configuration, in whichthe distal portion 202 assumes its curved configuration when thedelivery catheter 304 is withdraw (FIG. 17B), or any other element ofthe delivery assembly 300 that may radially constrict the distal portion202 of the shunt 200 is withdrawn. The distal end 202 of the shunt 200is biasedly curved in a suitable angle towards and/or configured to beoriented towards the IPS wall 114, so that the distal end 202 having thetissue penetrating member 250 is configured for piercing the IPS wall114 and arachnoid layer 115 creating anastomosis 140 and/or forimplantation of the shunt 200′ into the CP angle cistern 138.

FIGS. 18A-B illustrates another exemplary distal portion 202 of theshunt 200′ according to the embodiments of the disclosed inventions. Thedistal portion 202 of the shunt 200′ includes the flexible elongatetubular structure according to the disclosed inventions, and furthercomprises a plurality of slots 254 (e.g., cuts, openings, perforations,or the like, or combinations thereof) formed within the tubularstructure (FIG. 18A). The slots 254 are configured to selectively weakenthe axial and flexural strength of the tubular structure causing thedistal portion 202 to be more susceptible to bending or folding, whenthe distal portion 202 is subjected to an external force, for example,when the distal end 202 comes in contact with an object, such as theconduit 400 of FIGS. 12 and 14A-F. As shown in FIG. 18B, the slots 254are configured to remain closed due to the bend of the distal portion202 of the implanted shunt 200′, so that blood flow through the shunt200′ is prevented or avoided.

FIGS. 19A-B illustrates yet another exemplary distal portion 202 of theshunt 200′ according to the embodiments of the disclosed inventions. Thedistal portion 202 includes an elongated member 280 (e.g., leg,kickstand, or the like) configured to position the distal portion 202 ofthe shunt 200′ in the proper angle and orientation relative to the IPSwall 114. The elongated member or leg 280 includes a first end 281coupled to the distal portion 202 of the shunt 200′ in a hinge-likeconfiguration, and a second end 282 coupled to a pull wire 288. The leg280 further includes a stand or foot 283 at the second end 282configured to assist and stabilize the distal end 202 of the shunt 200′at the desired position within the IPS 102 (FIG. 19B). The leg 280 iscomposed of any suitable biocompatible material, according to thedisclosed inventions. The leg 280 may be attached to the distal portion202 of the shunt 200′ at the first end 281 (e.g. hinge, bonded, weldedor other movable attachment) or may be a cut-out of the shunt 200′tubular structure. The leg 280 comprises a delivery configuration foradvancement through the delivery catheter 304 or any other elements ofthe delivery assembly 300 (FIG. 19A), and a deployed configuration, inwhich the leg 280 assists and stabilizes the distal end 202 of the shunt200′ at the desired position within the IPS 102 (FIG. 19B). Byapplication of suitable retrograde force to the pull wire 288 coupled tothe second end 282 of the leg 280, the leg 280 moves in a backwarddirection so that the foot 280 contacts the lower portion of the IPS 102(e.g., “stands” on the IPS wall 117 opposite to the IPS wall 114),supporting and stabilizing the distal end 202 of the shunt 200′, asshown in FIG. 19B.

FIGS. 20A-F illustrate the delivery assembly 300 in accordance with oneembodiment of the disclosed inventions. The delivery assembly 300includes the delivery catheter 304, the shunt 200 coaxially disposedwithin the delivery catheter 304, and the elongate pusher member 310 310coaxially disposed within the shunt 200. The tissue penetrating member306 (e.g., surgical tool) is disposed on the distal portion 354 of theelongate pusher member 310 (e.g., piercing micro-wire). The elongatepusher member 310 includes one or more engaging members 312 disposed onan outer surface 311 of the elongate pusher member 310, and the shunt200 includes one or more engaging members 242 disposed on an inner wallsurface 208 of the shunt 200 to form a mechanical interaction with theone or more engaging members 312 of the elongate pusher member 310 (FIG.20A). The engaging member 242 of the shunt 200 (i.e., first engagingmember) protrudes and/or extends radially inward from the inner wall 208of the shunt 200, the engaging member 312 of the elongate pusher member310 (i.e., second engaging member) protrudes and/or extends radiallyoutward towards the inner shunt wall 208. The second engaging memberengages the first engaging member to thereby advance the distal portion202 of the shunt 200 from the IPS 102 into the CP angle cistern 138 onthe tissue penetrating member 306 (FIG. 20E). The engaging members 312and 242 may include protrusions, balls, collars, or the like, orcombinations thereof, or any other suitable configurations. When theengaging members 312 of the elongate pusher member 310 and the engagingmembers 241 of the shunt 200 meet and engage with each other (FIGS. 20Band 20E), advancement of the elongate pusher member 310 and penetratingelement 306 simultaneously advances the shunt 200 into the target ortarget penetration site, according to the disclosed inventions. Theengaging members 312 and 242 are configured to be engaged in a one-waydirection (i.e., forward in the direction of the penetration site of theIPS wall 114, distally toward the subarachnoid space 116—FIGS. 20B, 20Dand 20E), so that the engaging members 312 and 242 are disengaged whenthe elongate pusher member 310 having the penetrating element 306 iswithdrawn from the delivery catheter 304 or moved proximally (FIG. 20F).

The tissue penetrating member 306 comprises the elongate pusher member310 and a tissue penetrating distal tip, the elongate pusher member 310extends though the valve 209, lumen 207, and distal opening 201 of theshunt 200, respectively, wherein the elongate pusher member 310 ismoveable relative to the shunt 200 so that the tissue penetrating 306distal tip may be advanced out of, and withdrawn into, a distal opening201 of the shunt 200 in communication with the lumen 207, whereinadvancing the distal portion 202 of the shunt 200 from the IPS 102 intothe CP angle cistern 138 comprises advancing the elongate pusher member310 so that the tissue penetrating 306 distal tip penetrates through thedura mater tissue wall of the IPS 114, and through the arachnoid tissuelayer 115, respectively, into the CP angle cistern 138, with the distalportion 202 of the shunt 200 being carried on the tissue penetratingmember 306 (FIGS. 20A-E). When deploying the shunt 200, the methodfurther comprises, after advancing the distal portion of the shunt intothe CP angle cistern, withdrawing the tissue penetrating member 306through the distal opening 202, lumen 207 and valve of the shunt 200,respectively, wherein CSF flows through the respective distal opening201, lumen 207 and valve 209 of the shunt 200 after withdrawal of thetissue penetrating member 206 (FIG. 20F). When deploying the shunt 200,the method further comprises advancing the delivery catheter 304 intothe IPS 102 with the shunt 200 and tissue penetrating member 306 atleast partially disposed in the delivery lumen 305 of the deliverycatheter 304, the delivery catheter 304 having a distal opening incommunication with the delivery lumen 305 through which the respectivetissue penetrating member 306 and shunt 200 may be advanced into the CPangle cistern 138. The method of deploying the shunt further comprises,adjusting a rotational orientation of the delivery catheter 304 about anaxis of the delivery catheter 304 so that the tissue penetrating distaltip of the tissue penetrating member 306 is thereafter advanced out ofthe distal opening of the delivery catheter 304 into contact with thedura IPS wall 114 at an angle in a range of 30 degrees to 90 degreesthereto, prior to advancing the tissue penetrating member 306 into theCP angle cistern 138. The method further comprises imaging the shuntwhile deploying the shunt in the patient.

It should be appreciated that the aspects, features and functions of theengaging members 312 of the elongate pusher member 310 and the engagingmembers 241 of the shunt 200, described in FIGS. 20A-B, may beincorporated into the delivery assembly 300′, so that the tissuepenetrating member 250 coupled to a guidewire assists with theadvancement of the shunt 200′ into the target site (FIGS. 5E-I), and isconfigured to be disengaged and removed from the implanted shunt 200′(FIG. 5J).

Referring back to FIGS. 20A-F, the delivery catheter 304 includes adeflecting element 370 coupled to or disposed on the distal portion 344of the delivery catheter 304. The deflecting element 370 includes atubular configuration having an angled inner ramp 375 and a sideaperture 377. The deflecting element 370 is formed of suitablebiocompatible metals, alloys, polymers or their like, or combinationsthereof. The deflecting element 370 and particularly, the ramp 375, maybe formed of relatively stiff and non-deformable materials, or becovered with a relatively stiff polymeric coating (e.g.,polytetrafluoroethylene “PTFE”, polyethyleneterephthalate “PET”). Thedeflecting element 370 may further include radio-opaque materials orinclude markings for purposes of imaging, according to the disclosedinventions. The deflecting element 370 and ramp 375 are configured todeflect the tissue penetrating element 306, elongate pusher member 310,and shunt 200 engaged to the elongate pusher member 310, towards theaperture 377, so that the tissue penetrating element 306, elongatepusher member 310, and shunt 200 are advanced out of the distal portion344 of the delivery catheter 304 in a suitable angle for piercing theIPS wall 114 and the arachnoid layer 115 for implantation of the shunt200 into the target site (FIG. 20B), according to the disclosedinventions.

Prior to the piercing of the IPS wall 114 to create anastomosis andaccess the CP angle cistern 138, the proper orientation of the distalportion 344 of the delivery catheter 304, particularly, the properorientation of the deflecting element 370 and/or aperture 377, may beverified according to the imaging methods previously disclosed. Whenneeded, the positioning and orientation of the deflecting element 370disposed on the distal portion 344 of the delivery catheter 304 may beadjusted, for example, by applying a rotational force directly to thebody of the delivery catheter 304, or to the elongate pusher member 310,if the member 310 is engaged to the delivery catheter 304.

Alternatively, a stabilizing element 380 may be used for positioning,orienting, and/or stabilizing the distal end 344 of the deliverycatheter 304, and/or the aperture 377 of the deflecting element 370within the IPS 102, as shown in FIGS. 20C-D. The stabilizing element 380of the delivery assembly 300 may be coaxially disposed with the guidecatheter 320, and includes a distal portion 382 configured to radiallyexpand and engage the IPS 102 walls 114, 117 (i.e., diameter d₁, asshown in FIG. 2) when the stabilizing element 380 is advanced out of thedistal portion 324 of the guide catheter 320 and/or the guide catheter320 is withdrawn exposing the distal portion 382 of the stabilizingelement 380. The stabilizing element 380 may be composed of any suitablebiocompatible shape memory and/or expandable materials according to thedisclosed inventions.

In the embodiments of FIGS. 20C-D, the distal portion 382 of thestabilizing element 380 includes a spiral configuration. In otherembodiments, the distal portion 382 of the stabilizing element 380 mayinclude any suitable configuration, such as a coil, stent, expandablefoams, balloons, or combinations thereof, configured to engage the IPS102 walls 114, 117 and assist with the position, orientation, and/orstability of the distal end 344 of the delivery catheter 304, and/or theaperture 377 of the deflecting element 370 within the IPS 102. Whendeployed, the stabilizing element 380 stabilizes the position of thedistal end 344 of the delivery catheter 304, and/or the aperture 377 ofthe deflecting element 370 preventing movement of the catheter distalend 344 and deflecting element 370 within the IPS 102 while the IPS wall114 is being pierced (FIG. 20D).

FIG. 20E illustrates the further advancement of the shunt 200 into thetarget site by the advancement of the elongate pusher member 310 (i.e.,via engagement of the respective engaging members 312 and 242) of theembodiments of FIGS. 20A-D, along with the withdrawal of the deliverycatheter 304 (not shown). Once the shunt 200 is deployed in the targetsite, the elongate pusher member 310 having the tissue penetratingelement 306 is withdrawn (i.e., disengagement of the respective engagingmembers 312 and 242), as shown in FIG. 20F. Additionally, the anchoringmechanism 229 of the shunt 200 is deployed to secure the distal portion202 of the shunt 200 in the target site, according to the disclosedinventions.

FIGS. 21A-D illustrate the delivery assembly 300′ having one or morestabilizing element 380 in accordance with one embodiment of thedisclosed inventions. The delivery assembly 300′ includes the guidecatheter 320, the delivery catheter 304 and the delivery guidewire 308.The delivery catheter 304 of the delivery assembly 300′ includes thestabilizing element 380 that extends from or is disposed on the distalportion 344 of the delivery catheter 304, and the deflecting element 370disposed in the distal portion 344 of the delivery catheter 304. Asshown in FIG. 21A, the stabilizing element 380 comprises a firststabilizing element 380 a, a second stabilizing element 380 b, and thedeflecting element 370 disposed between the stabilizing elements 380 aand 380 b. The stabilizing elements 380 a and 380 b include inflatableballoons that may be inflated with contrast dye for imaging proposes,according to the disclosed inventions. In some embodiments, thestabilizing elements 380 a and 380 b may include expandable coils,stent, foams, or the like, or combinations thereof. The deflectingelement 370 includes the inner angle ramp 375 and the side aperture 377,according to the disclosed inventions (FIGS. 20A-D).

As shown in FIG. 21A, the stabilizing elements 380 a and 380 b aredeflated and/or radially constricted in the delivery configurationwithin the IPS 102. Once the proper position and orientation of thedistal portion 344 of the delivery catheter 304 and/or of the aperture377 is achieved according to the methods of the disclosed inventions,the stabilizing elements 380 a and 380 b are inflated and/or radiallyexpanded, as shown in FIG. 21B, stabilizing the delivery catheter 304and/or the aperture 377 within the IPS 102. As shown in FIGS. 21C-D, theshunt 200′ incorporating the tissue penetrating member 250 is advancedthrough the delivery catheter 304, meeting the ramp 375 of thedeflecting element 370, so that the shunt 200′ is deflected towards theaperture 377 and the tissue penetrating member 250 contacts and piercesthe IPS wall 114 and the arachnoid layer 115 in a suitable angle forcreation of the anastomosis 140 and implantation of the shunt 200′ intothe target site (FIG. 21E), according to the disclosed inventions. Asshown in FIG. 21E, the distal anchoring mechanism 229 incorporated inshunt 200′ expands, anchoring the shunt 200′ within the CP angle cistern138 and further allowing CSF drainage through the shunt 200′. In theembodiments of FIGS. 21C-E, the shunt 200′ comprises an elliptecotconfiguration that will be described in further detail below. It shouldbe appreciated that the embodiments and methods disclosed in FIGS. 21A-Ecan include any features and steps disclosed herein, including featuresand steps disclosed in connection with different embodiments (e.g.,shunt 200, delivery assembly 300), in any combination as appropriate.

FIGS. 22A-G illustrate an exemplary shunt 200 constructed and implantedaccording to embodiments of the disclosed inventions. The shunt 200includes the anchoring mechanism 227 and a duck-bill valve 209 in theproximal portion 204, the anchoring mechanism 229 in the distal portion202, and the elongate body 203 extending therebetween. The anchoringmechanisms 227 and 229 include a malecot configuration having aplurality of respective deformable elements 227 a and 229 a (e.g., arms)that are disposed radially outward in the deployed configuration (FIGS.22A and 22F-G). The anchoring mechanism 227 and 229 are formed byconcentric parallel or radially spaced cuts 222 along the length of therespective proximal 204 and distal 202 portions of the shunt 200,forming the arms 227 a and 229 a (FIGS. 22B-D). FIGS. 22C-D illustrateexemplary patterns and dimensions of the cuts 222 in the respectiveproximal 204 (FIG. 22C) and distal 202 (FIG. 22D) portions. It should beappreciated that the patterns and dimensions of the cuts 222 in theproximal portion 204 may be similar or dissimilar from the patterns anddimensions of the cuts 222 in the distal portion 202. Each deformableelement 227 a and 229 a has a respective hinge-like point 227 b and 229b (e.g., living hinge, joint, or the like). As shown in FIG. 22A, thehinge-like points 227 b and 229 b are configured to move radiallyoutward from the axis of the shunt 200 in a hinge-like fashion, allowingthe arms 227 a and 229 a to be outwardly disposed so that the shunt 200is anchored at the target site. Anchoring mechanisms can have apreformed expanded or deployed configuration (e.g., configuration ofFIGS. 22A, 22F-G), for example, when constructed from super-elasticmaterials such as Nitinol. The deployed anchoring mechanism 227 engagesthe jugular bulb 108, the IPS wall 117, and/or another portion of theIPS 102, anchoring the proximal portion 204 of the shunt 200 within thejugular vein 106, so that the valve 209 is disposed within the jugularvein 106. Alternatively, the anchoring mechanism 227 may engage the IPSwalls 114 and 117 at the junction 118 (not-shown). The deployedanchoring mechanism 229 secures the distal portion 202 of the shunt 200within the CP angle cistern 138 (FIGS. 5H-J), so that CSF flows throughthe implanted shunt 200 into the jugular vein 106.

Additionally, the shunt 200 may include an interlocking element 294(e.g., clasp) coupled to the proximal portion 204 of the shunt 200(FIGS. 22B and 22E). The interlocking element 294 is configured toengage and disengage with an interlocking element coupled to the distalportion of the delivery assembly (not shown) for deployment of the shunt200 at the target site. FIG. 22E illustrates an exemplary pattern usedfor laser cutting a tubular portion of super-elastic material to form anembodiment of the interlocking element 294.

Dimensions referenced in FIG. 22B, are provided in inches. It should beappreciated that the dimensions depicted in FIG. 22B are exemplarydimensions of the shunt 200, which are not intended to limit theembodiment of FIGS. 22A-G.

FIGS. 23A-E illustrate another exemplary shunt 200 constructed andimplanted according to embodiments of the disclosed inventions. As shownin FIG. 23A, the shunt 200 includes the anchoring mechanism 227 and theduck-bill valve 209 in the proximal portion 204, the anchoring mechanism229 in the distal portion 202, and the elongate body 203 extendingtherebetween. The body 203 of the shunt 200 comprises slidably disposedconcentric tubular elements, as shown in FIGS. 6E-F, for selectiveelongation and/or adjustment of the shunt length L₂ (FIG. 6) accordingto the anatomy of the patient (i.e., target site for implantation of theshunt 200. The anchoring mechanisms 227 and 229 include a flower-likeconfiguration having a plurality of respective deformable elements 227 aand 229 a (e.g., petals) that are disposed radially outward in thedeployed configuration. The deformable petals 227 a and 229 a are formedby concentric parallel and/or radially spaced cuts 230 along the lengthof the respective proximal 204 and distal 202 portions of the shunt 200,as shown in FIG. 23B. The number of petals 227 a and 229 a depend on thenumber of cuts 230 formed into the respective proximal 204 and distal202 portions. The petals 227 a and 229 a are configured to invert, foldand/or expand into their deployed configurations when the shunt 200 isimplanted, as shown in FIGS. 23A, and 23C-D. As shown in FIGS. 23C-D,the distal anchoring mechanism 229 is deployed by advancement of theshunt 200 and/or withdrawal of the delivery catheter 304, so that thepetals 229 a invert, fold and/or expand, engaging the arachnoid layer115 and securing the distal portion 202 of the shunt 200 within the CPangle cistern 138, as shown in FIG. 23D.

FIGS. 24A-E illustrate yet another exemplary shunt 200 constructed andimplanted according to embodiments of the disclosed inventions. Theshunt 200 includes the anchoring mechanism 227 and an interlocking valve209 in the proximal portion 204, the anchoring mechanism 229 in thedistal portion 202, and the elongate body 203 extending therebetween.The body 203 of the shunt 200 comprises a spring/coil-like body, asshown in FIG. 6GH, for selective elongation and/or adjustment of theshunt length L₂ (FIG. 6) according to the anatomy of the patient (i.e.,target site for implantation of the shunt 200). Further, thespring/coil-like body 203 of the shunt 200 is configured to applytensional force, at least, between the proximal portion 204 and thedistal portion 202 of the shunt 200 maintaining the implanted shunt 200properly anchored in the target site (e.g., preventing movement of shuntor a loosely anchored shunt). The shunt 200 is composed of shape-memorymaterials, such as super-elastic nickel titanium alloy, known asNitinol® or other suitable material, so that the proximal portion 204forming the anchoring mechanism 227, and the distal portion 202 formingthe anchoring mechanism 229, comprise helical-coil or spring-likeconfigurations when deployed, as shown in FIGS. 24A-C. The shunt 200 iselongated for advancement through the delivery assembly 300 in thedelivery configuration (FIG. 3B), and assumes the deployed configurationwhen the delivery assembly 300 that radially constricts the shunt 200 iswithdrawn and/or the shunt 200 is advanced out of the delivery assembly300 (FIGS. 24A-C), so that the anchoring mechanisms 227 (FIGS. 24A and24C) and 229 (FIGS. 24A-B) are deployed, securing the implanted shunt200 in the target site. CSF flows through the implanted shunt 200, fromthe CP angle cistern 138 entering the shunt lumen 207 from distalportion 202 of the shunt (FIG. 24B) and out of valve 209 at the proximalportion 204 of the shunt (FIG. 24D) into the jugular vein 106. As shownin FIG. 24D, the valve 209 comprises a concentric gland seal housed onthe proximal portion 204 of the shunt 200 with a slit exposing theopening of the valve, as also shown in FIG. 6L. FIG. 24E illustrates analternative embodiment of the shunt 200 of FIG. 24A, in which the shunt200 comprises the spring/coil-like configuration in substantially theentire length L₂ of the shunt 200 (i.e., from the proximal portion 204to the distal portion 202, including the body 203) in the deployedconfiguration.

FIGS. 25A-G illustrate yet another exemplary shunt 200 constructed andimplanted according to embodiments of the disclosed inventions. As shownin FIG. 25A, the shunt 200 includes the anchoring mechanism 227 and theduck-bill valve 209 in the proximal portion 204, the anchoring mechanism229 in the distal portion 202, and the elongate body 203 extendingtherebetween. The body 203 of the shunt 200 comprises slidably disposedconcentric tubular elements, as shown in FIGS. 6E-F, for selectiveelongation and/or adjustment of the shunt length L₂ (FIG. 6) accordingto the anatomy of the patient (i.e., target site for implantation of theshunt 220). The deployed anchoring mechanism 227 disposed on theproximal portion 204 of the shunt 200 comprises a spiral configurationfor anchoring the proximal portion 204 of the shunt 200 within thejugular vein 106 by engaging the jugular bulb 108, the IPS wall 117 andanother portion of the IPS 102, so that the duck-bill valve 209 isdisposed within the jugular vein 106 (FIG. 25G). Alternatively, theanchoring mechanism 227 may engage the IPS wall 114 and 117 at thejunction 118 (not shown). The anchoring mechanism 229 of the distalportion 202 of the shunt 200 comprises a retrograde-barb configuration(FIGS. 25A-F), so that when the anchoring mechanism 229 is in thedelivery configuration, the tissue penetrating member 250 formed of anelongated cannula is folded over a portion 202″ of the distal portion202 of the shunt 200 (e.g., radially constrained by the deliverycatheter 304, FIG. 25B-C), and when the anchoring mechanism 229 is inthe deployed configuration, the tissue penetrating member 250 unfolds orexpands from the portion 202″ in a hinge-like fashion (FIGS. 25A and25E-F). The portion 202″ of the distal portion 202 is configured toradially expand in the deployed configuration, supporting andstabilizing the distal end 202 of the shunt 200 within the IPS 102(FIGS. 25A and 25E-F). As shown in FIGS. 25B-C, the anchoring mechanism229 is advanced thorough the delivery catheter 304 into a target sitewithin the IPS 102 (e.g., at a location proximate the jugular bulb 108or the jugular tubercle (not shown)). The anchoring mechanism 229 isfurther advanced within the IPS 102 and/or the delivery catheter 304 iswithdrawn (FIG. 25C), so that the tissue penetrating member 250 unfolds(FIG. 25D). By application of suitable retrograde force to the shunt200, the unfolded tissue penetrating member 250, in contact with the IPSwall 114, pierces the dura mater of the IPS wall 114 and the arachnoidlayer 115 creating anastomosis 140 into the CP angle cistern 138 (FIGS.25E-F). The expanded portion 202″ of the anchoring mechanism 229supports and stabilizes the distal end 202 of the deployed shunt 200(e.g., contacting/“seating on” the IPS wall 117), as shown in FIGS. 25Aand 25E-F.

FIGS. 26A-G illustrate another exemplary shunt 200 constructed andimplanted according to embodiments of the disclosed inventions. As shownin FIG. 26A, the shunt 200 includes the anchoring mechanism 227 andvalve 209 in the proximal portion 204, the anchoring mechanism 229 inthe distal portion 202, and the elongate body 203 extendingtherebetween. As shown in FIG. 26A, the body 203 and distal portion 202of the shunt 200 comprise a self-expandable stent having anelastomeric/polymeric cover/liner, and/or stent-graft configuration, asshown in FIGS. 12 and 13A-C for the conduit 400. The shunt 200 iselongated for advancement through the delivery catheter 304 in thedelivery configuration (FIG. 26B), and assumes the deployed/expandedconfiguration when the delivery catheter 304 that radially constrictsthe shunt 200 is withdrawn and/or the shunt 200 is advanced out thedistal portion 344 (e.g. distal end opening 346) of delivery catheter304 (FIGS. 26A, 26C-E), so that the anchoring mechanism 229 (FIGS. 26Aand 26C-E) self-expands, securing the implanted shunt 200 in the targetsite. The anchoring mechanism 227 secures the proximal portion 204 ofthe shunt 200 within the jugular vein 106 by engaging the jugular bulb108 and/or the jugular vein 106, the IPS wall 117 and another portion ofthe IPS 102, so that the valve 209 is disposed within the jugular vein106 (FIGS. 26A and 26H). CSF flows through the implanted shunt 200, fromthe CP angle cistern 138 entering the shunt lumen 207 from distalportion 202 of the shunt (FIGS. 26A and 26C) and out of valve 209 at theproximal portion 204 of the shunt (FIG. 26A) into the jugular vein 106.As shown in FIGS. 26A and 26F-G, the valve 209 comprises a concentricgland seal housed on the proximal portion 204 of the shunt 200 with aslit exposing the opening of the valve, as also shown in FIG. 6L. Thedelivery assembly 300 further comprises an interlocking mechanism 290configured to detachably couple the shunt 200 to the delivery catheter304, as shown in FIG. 26F. The interlocking mechanism 290 includes afirst interlocking element 292 (e.g., clasp) coupled to the deliveryassembly 300 (e.g., via a push wire) and a second interlocking element294 (e.g., clasp) coupled to the shunt 200 proximal portion 204 (e.g.,attached to the valve 209). Once the shunt 200 is properly disposed atthe target site, withdrawal of the delivery catheter 304 allows theinterlocking mechanism 290 to be uncoupled (FIG. 26G). The interlockingelement 294 coupled to the shunt 200 proximal portion 204 also allowsfor subsequent capture, recovery and/or withdrawal of the implantedshunt 200 (e.g., snare catheter).

FIGS. 27A-E illustrate another exemplary shunt 200 constructed andimplanted according to embodiments of the disclosed inventions. As shownin FIG. 27A, the shunt 200 includes the anchoring mechanism 227 andvalve 209 in the proximal portion 204, the anchoring mechanism 229 inthe distal portion 202, and the elongate body 203 extendingtherebetween. As shown in FIGS. 27A-B, the body 203 of the shunt 200comprises a self-expandable stent having an elastomeric/polymericcover/liner, and/or stent-graft configuration, as shown in FIGS. 12,13A-C and 26A-E. The deployed anchoring mechanisms 227 and 229 of theshunt 200 comprises a radially expanded configuration (e.g., mesh orwired sphere, elliptic, wired frame or basket, or the like, orcombinations thereof) for anchoring the shunt 200 at the target site(FIG. 27A-B). The anchoring mechanisms 227 and 229 (FIGS. 27A-D)self-expand when the shunt 200 is implanted, thereby securing theimplanted shunt 200 in the target site. The anchoring mechanism 227 ofthe proximal portion 204 of the shunt incorporates the valve 209. Thevalve 209 comprises a wire frame partially covered with anelastomeric/polymeric liner, so that the CSF flow is regulated by thepercentage of liner covering over the wire frame (FIGS. 27A and 27C).For example, the flow rate is lower when the wire frame is substantiallycovered by the liner, as shown in FIG. 27C, and the flow rate is largerwhen the wire frame has less liner coverage, as shown in FIG. 27A. Asshown in FIGS. 27C-E, the delivery assembly 300 further comprises aninterlocking mechanism 290 configured to detachably couple the shunt 200to the delivery catheter 304. The interlocking mechanism 290 includes afirst interlocking element 292 (e.g., claw) coupled to the deliverycatheter 304 and a second interlocking element 294 (e.g., ring) coupledto the shunt 200 proximal portion 204 (e.g., attached to the valve 209).Once the shunt 200 is properly disposed at the target site, withdrawalof the delivery catheter 304 and uncoupling of the interlockingmechanism 290 (e.g., disengaging the claw, as shown in FIG. 27E) allowsdeployment of the shunt 200 (FIG. 27D). The interlocking element 294(e.g., ring) coupled to the shunt 200 proximal portion 204 also allowsfor subsequent capture, recovery and/or withdrawal of the implantedshunt 200 (e.g., claw tool/catheter) or revision of valve 209 inproximal portion 204.

Alternatively, the embodiment of shunt 200 depicted in FIGS. 27A-E canbe configured for deployment in IPS 102 using a two-step process. First,the body 203 of the shunt 200 comprising a self-expandableelastomeric/polymeric cover/liner, and/or stent-graft configuration, canbe deployed in IPS 102. In some embodiments, the cover/liner orstent-graft element resides only within the IPS 102, while in otherembodiments, deployment of the cover/liner or stent-graft elementincludes the step of creating the anastomotic connection between the IPS102 and the CSF-filled subarachnoid space of the CP angle cistern 138(e.g., FIGS. 26B-E). In a second step, a self-expanding wire form (e.g.,comprising the proximal and distal anchoring mechanisms 227 and 229,respectively, and a stent-like body portion configured to reside withinthe cover liner or stent-graft) can be delivered through the previouslydeployed cover/liner and/or stent graft (e.g., FIG. 27B). The anchoringmechanisms 227 and 229 (FIGS. 27B-D) self-expand as the wire form isdeployed out the cover/liner and/or stent graft in the CP angle cistern138 (i.e., mechanism 229) and jugular vein 106 (i.e., mechanism 227),thereby securing the implanted shunt 200 in the target site. A partiallycovered wire frame comprising the proximal anchoring mechanism 227 formsvalve 209 with the cover/liner and/or stent graft as previouslydisclosed.

FIG. 28 illustrates an exemplary shunt 200 constructed according toembodiments of the disclosed inventions. The shunt 200 includes theanchoring mechanism 227 and a duck-bill valve 209 in the proximalportion 204, the anchoring mechanism 229 in the distal portion 202, andthe elongate body 203 extending therebetween, and further including ananchoring mechanism 223. The anchoring mechanisms 223, 227 and 229include a plurality of respective deformable elements 223 a, 227 a and229 a (e.g., wires, loops) that are disposed radially outward in thedeployed configuration. The deformable elements 223 a, 227 a and 229 aare self-expanding (i.e., expanding from the delivery configuration intothe deployed configuration) and configured to move radially outward fromthe axis of the shunt 200 allowing the shunt 200, including the body203, to be anchored at the target site. The anchoring mechanism 227 isconfigured to engage the jugular bulb 108, the jugular vein 106, the IPSwall 117, and/or another portion of the IPS 102, anchoring the proximalportion 204 of the shunt 200 within the jugular vein 106, so that thevalve 209 is disposed within the jugular vein 106. The anchoringmechanism 223 is configured to engage the IPS walls 114 and 117,anchoring the body 203 within the IPS 102, and the anchoring mechanism229 is configured to engage the arachnoid layer 115 anchoring the distalportion 202 of the shunt 200 within the CP angle cistern 138.

FIGS. 29A-G illustrates an alternative embodiment of the shunt 200constructed and implanted according to embodiments of FIGS. 12 and 14A-Hof the disclosed inventions. In the embodiment of FIGS. 29A-G, the shunt200 is coupled to the conduit 400; the shunt 200 further includes thevalve 209 in the proximal portion 204. Dual conical Nitinol coils 229 aform a piercing cone (not shown) when constrained by the deliverycatheter 304 and conduit 400; coils 229 a of the piercing cone (e.g.,pencil tip configuration) are delivered to IPS 102 in a constraineddelivery configuration, thereby providing a sharp penetrating memberthat passes through dura of IPS wall 114 and arachnoid layer 115. Coils229 a can be self-expanding to separate from the penetrating cone formand expand within the subarachnoid space after passing through the dura114 and arachnoid 115 to compress or pin down the penetrated arachnoidlayer 115 within the CP angle cistern 138. Alternatively, the coils 229a can be mechanically actuated from a penetrating cone to a deployedconfiguration, according to previously disclosed embodiments of theanchoring mechanism 229. As shown in FIGS. 29A, 29C-D, and 29F-G, theanchoring mechanisms 227 and 229 are incorporated or disposed on theconduit 400. The conduit 400 comprises a self-expandable stent having anelastomeric/polymeric cover/liner, and/or stent-graft configuration, asshown in FIG. 12. The anchoring mechanism 229 comprises a plurality ofdeformable elements 229 a (e.g., coils) and a tubular neck 229 b (FIGS.29A, 29C-D). The plurality of deformable elements 229 a are configuredto move radially outward from the axis of the shunt 200 and/or conduit400, and alternatively, the elements 229 a are also configured to movedownwards (FIGS. 29A, 29C-D). The neck 229 b is configured to bedisposed within the anastomosis channel 140 in the deployedconfiguration (FIGS. 29A, 29C-D). Additionally, the anchoring mechanism229 includes engaging members 229 k (e.g., spring wires, balloons,claws, barbs, or the like, or combinations thereof) coupled to thetubular neck 229 b and configured to move radially outward and upwards(FIG. 29D). Further, the neck 229 b and/or engaging members 229 kcomprise a penetration stop preventing the penetrating member (e.g.,306, 250, 350, penetrating cone) and/or the shunt 200/200′ from beingdeployed beyond a suitable distal length into the CP angle cistern 138,allowing suitable clearance between the distal tip of the shunt 200/200′and the brain stem 112, while avoiding abutting or the damaging brainstem 112.

As shown in FIG. 29D, the anchoring mechanism 229 is configured tocompress or pin down the arachnoid layer 115 with the deployed elements229 a against the dura mater IPS wall 114 with the deployed members 229k, to prevent occlusion of the shunt lumen 207 (e.g., by arachnoidmater). The deployed anchoring mechanism 227 engages the jugular bulb108, the jugular vein 106, the IPS wall 117, and/or another portion ofthe IPS 102, anchoring the proximal portion 204 of the shunt 200 and/orconduit 400 within the jugular vein 106, so that the valve 209 isdisposed within the jugular vein 106 (FIGS. 29A, 29F-G). Valve 209 canhave a windsock-like configuration, formed from a collapsible, mesh-likeframework of biocompatible polymeric material (e.g., PTFE, ePTFE, i.e.,expanded polytetrafluoroethylene, PET). In its open form (e.g., undernormal differential pressure between the subarachnoid space and venoussystem), CSF flows from the CP angle cistern 138 through the shunt lumen207 and out through the pores of windsock valve 209 into the jugularvein 106. Windsock valve 209 can collapse on itself (e.g., where venousblood pressure exceeds the intracranial pressure in the subarachnoidspace such during coughing or sneezing events) to prevent the backflowof blood through shunt 200 into the subarachnoid space 116. As shown inFIG. 29G, the circulation of venous blood flow around the proximalportion 204 of the shunt 200 agitates the valve 209, minimizing,deterring, or avoiding growth of endothelial cells and clogging of thelumen 207 opening at the proximal portion 204 of the shunt 200. Aspreviously disclosed with the embodiments of shunt 200 depicted in theFIG. 27, the embodiments of shunt 200 shown in FIG. 29 can be deployedin a two-step process (e.g., deployment of conduit 400 in at least theIPS 102 in a first step, and deployment of a self-expanding wire formcomprising the proximal and distal anchoring mechanisms 227 and 229, astent-like body portion, and valve 209 in a second deployment step).

FIGS. 30A-F illustrate another exemplary shunt 200 constructed andimplanted according to embodiments of the disclosed inventions. Theshunt 200 includes the anchoring mechanism 227 and the duck-bill 209 inthe proximal portion 204, the anchoring mechanism 229 and tissuepenetrating member 250 in the distal portion 202, and the elongate body203 extending therebetween. The body 203 of the shunt 200 comprises aspring/coil-like body, as shown in FIG. 6GH, for selective elongationand/or adjustment of the shunt length L₂ (FIG. 6) according to theanatomy of the patient (i.e., target site for implantation of the shunt220). Further, the spring/coil-like body 203 of the shunt 200 isconfigured to apply tensional force, at least, between the proximalportion 204 and the distal portion 202 of the shunt 200 maintaining theimplanted shunt 200 properly anchored in the target site (e.g., limitingmovement of shunt or loosely anchored shunt). The shunt 200 may becomposed of thermoplastic elastomer (TPE), and the anchoring mechanisms227 and 229 may be composed of shape-memory materials, such assuper-elastic nickel titanium alloy, known as Nitinol® or other suitablematerial. The shunt 200 is elongated for advancement through thedelivery catheter 304 (FIG. 30B). The anchoring mechanisms 227 and 229comprise a T-bar tubular configuration, as shown in FIGS. 30A-F. Theanchoring mechanism 229 includes a first anchoring element 229 aconfigured to be disposed in the CP angle cistern 138, anchoring and/orholding the distal portion 202 of the shunt 200 against the arachnoidlayer 115 so that the tissue penetrating member 250 is disposed and heldadjacently to the arachnoid layer 115 when the shunt 200 is deployed(FIGS. 30A and 30C). The anchoring mechanism 229 further includes asecond anchoring element 229 b configured to be disposed within the IPS102 contacting the IPS wall 114, further anchoring and holding thedistal end 202 of the shunt 200 when interfacing with the firstanchoring element 229 a, as shown in FIGS. 30A and 30C. The deployedanchoring mechanism 227 engages the jugular bulb 108, the jugular vein106, the IPS wall 117, and/or another portion of the IPS 102, anchoringthe proximal portion 204 of the shunt 200 within the jugular vein 106,so that the valve 209 is disposed within the jugular vein 106, as shownin FIGS. 30A and 30-D-F. The delivery assembly 300 further comprises aninterlocking mechanism 290 configured to detachably coupled the shunt200 to the delivery catheter 304, as shown in FIGS. 30D-F. Theinterlocking mechanism 290 includes a first interlocking element 292(e.g., double clasps, claws) coupled to the delivery assembly 300 and asecond interlocking element 294 (e.g., annular recess) coupled to theshunt 200 proximal portion 204. Once the shunt 200 is properly disposedat the target site, withdrawal of the delivery catheter 304 anduncoupling of the interlocking mechanism 290 (e.g., disengaging the claw292 from the recess 294, as shown in FIG. 30E) allows deployment of theshunt 200 (FIGS. 30A and 30F). The interlocking element 294 (e.g.,annular recess) disposed in the proximal portion 204 of the shunt 200also allows for subsequent capture, interrogation, repair, recoveryand/or withdrawal of the implanted shunt 200 (e.g., claw tool/catheter).

FIG. 31 illustrates an alternative embodiment of the shunt 200constructed and implanted according to the embodiment of FIGS. 22A-G.The implanted shunt 200 shown in FIG. 31 includes an anchoring mechanism227 and a duck-bill valve 209 in the proximal portion 204, an anchoringmechanism 229 in the distal portion 202, and an elongate body 203extending therebetween. The anchoring mechanism 227 includes apre-curved configuration (e.g., “S” like shape) and may further includea stent disposed within the jugular vein 106, which may be attached tothe proximal portion 204 of the shunt 200. The stent portion of theanchoring mechanism 227 maintains the proximal portion of shunt 200 andduck-bill valve 209 in a relatively high blood flow area of the jugularvein to prevent occlusion of valve 209. Such stent portion preventsproximal portion 204 and valve 209 from being incorporated into the wallof the jugular bulb and vein by endothelial cells overgrowing theproximal portion 204 of the shunt 200, which can lead to shunt cloggingand failure.

FIG. 32 illustrates an alternative embodiment of the shunt 200constructed and implanted according to embodiment of FIG. 21E. Theimplanted shunt 200 includes the anchoring mechanism 229 and the tissuepenetrating member 250 in the distal portion 202 of the shunt 200. Theanchoring mechanism 229 comprises an elliptecot configuration, aspreviously disclosed.

FIGS. 33A-33C depict one embodiment of an interface between the tissuepenetrating element 306 and the shunt 200 constructed according toembodiments of the disclosed inventions. The tissue penetrating element306 includes a hollow tubular trocar configured to be coaxially disposedwithin the lumen 207 of shunt 200. The tissue penetrating element 306includes a curved distal portion (e.g., pre-curved, biasedlycurved-heat-set Nitinol, flexible, drivable distal portion via controlwires, or the like, or combinations thereof) with a sharpened, beveledtip configured to penetrate the IPS wall 114 and the arachnoid layer115. The shunt 200 also includes a curved distal portion 202 (e.g.,pre-curved, biasedly curved-heat-set Nitinol, flexible, or the like, orcombinations thereof). As shown in FIG. 33A, the respective curveddistal portions of the tissue penetrating element 306 and the shunt 200are depicted in an opposite directions. The lumen 207 of the shunt 200is configured to allow passage of the tissue penetrating element 306thereof, as shown in FIG. 33B. When the tissue penetrating element 306and the shunt 200 are disposed in a destructive interference (e.g.,opposed respective curved distal portions) the tissue penetratingelement 306 and shunt 200 create a straightened configuration, as shownin FIG. 33B. In this straight configuration, the tissue penetratingelement 306 and the shunt 200 can be navigated through the vasculaturevia the delivery catheter 304 until reaching the desired deploymentlocation along the IPS wall 114. At such location, the tissuepenetrating element 306 can be rotated relative to the shunt 200 suchthat the respective curved distal portions of the tissue penetratingelement 306 and the shunt 200 align along the same arcuate path having aconstructive interface cooperatively bending towards the IPS wall 114,as shown in FIG. 33C. The tissue penetrating element 306 can be advanceddistally from the shunt 200 to penetrate through IPS wall 114 andarachnoid layer 115 into the subarachnoid space 116, as previouslydescribed. The shunt 200 can then be advanced over the tissuepenetrating element 306 and be anchored in CP angle cistern 138 (e.g.,before, as, or after the tissue penetrating element 306 is withdrawnfrom the delivery assembly 300). The tissue penetrating element 306 andshunt 200 configuration of FIGS. 33A-33C advantageously allows thetissue penetrating element 306 and shunt 200 to be delivered in astraight configuration while tracking through the vasculature to the IPS102, and then rotated to a constructive interference of the curveddistal portions of the tissue penetrating element 306 and the shunt 200having a combined strength for penetrating through the IPS wall duramater 114 and arachnoid layer 115.

FIGS. 34A-34B illustrate another exemplary shunt 200 constructed andimplanted according to embodiments of the disclosed inventions. FIGS.34A-B depict side views of the shunt 200 having the anchoring mechanism227 extending from the proximal portion 204 of the shunt 200 comprisinga shepherd's hook or “J” like shape in the deployed configuration, andthe anchoring mechanism 229 extending from the distal portion 202 of theshunt 200 also comprising a shepherd's hook or “J” like shape in thedeployed configuration. The anchoring mechanisms 227 and 229 includerespective curved (e.g., pre-curved, biasedly curved, flexible, or thelike, or combinations thereof) proximal 204 and distal 202 portions ofthe shunt 200, forming their respective shepherd's hooks or “J” likeshape in the deployed configuration. FIG. 34B depicts a cross-sectionview of the shunt 200 deployed and implanted in the IPS 102, providing aconduit for one-way flow of CSF from the CP angle cistern 138 into thejugular vein 106. The anchoring mechanisms 227 and 229 are configured tosecure and anchor the shunt 200 in a desired location by engaging thetissue in the CP angle cistern 138 and jugular vein 106, respectively,as previously described. The shepherd's hooks or “J” like shape of theanchoring mechanisms 227 and 229 in the deployed configuration minimizeand/or prevent shunt occlusion and clogging by maintaining the openinginto the lumen 207 of the shunt 200 of the distal portion 202 (e.g., CSFinflow portion) separated, apart, or away from the arachnoid layer 115(FIG. 34B) and the opening out of the lumen 207 of the shunt 200 of theproximal portion 204 (e.g., CSF outflow portion, valve 209) separated,apart, or away from the wall of the jugular vein 106 (FIG. 34B). Theshunt 200 comprises a spring/coil-like body 203, as shown in FIGS. 34Aand 34B (interrupted line), for selective elongation and/or adjustmentof the shunt 200 length L₂ according to the anatomy of the patient(i.e., target site for implantation of the shunt 200). Further, thespring/coil-like body 203 of the shunt 200 is configured to applytensional force, at least, between the proximal portion 204 and thedistal portion 202 of the shunt 200 maintaining the implanted shunt 200properly anchored in the target site.

Several embodiments of the shunt 200 and/or the delivery system 300 havebeen previously described for penetrating the dura mater of the IPS wall114 and the arachnoid layer 115 with a penetrating element (e.g.,elongate pusher member 310, delivery catheters 304/304′/304″, piercingelements 306/250/350, shunt 200′, and/or system 300′). It should beappreciated that factors (e.g., design and clinical aspects) can beconsidered as to determine the embodiments, aspects and configurationsof the penetrating element of the system 300, for example: (a) the peakforce required to penetrate through tissue (i.e., IPS wall 114 duramater from within the IPS 102 and the arachnoid layer 115 into the CPangle cistern 138), which force is translated through the deliverysystem 300 from a peripheral access point such as a delivery catheterinserted at the femoral vein (e.g., proximal portion of a delivery guidewire, catheter, or tool); (b) the tissue damage and severity of thetrauma caused from the penetrating/piercing step or force (a) applied tothe IPS wall 114 dura mater and arachnoid layer 115; (c) the extent towhich the penetration site seals around the deployed shunt or haspotential for leaking blood or CSF through the anastomosis 140; (d) theextent of tissue deformation during the penetrating/piercing step orforce (a) applied to the IPS wall 114 dura mater and arachnoid layer 115(e.g., the extent that IPS wall 114 dura mater and/or arachnoid layer115 expand toward brain stem 116 before the penetrating element passesthrough the tissue); and (e) the extent that the penetrating elementresists bending or buckling while penetrating tissue and/or that suchpenetrating element requires additional support (e.g., an outer sheath)to translate the forces required to penetrate tissue.

FIG. 35 depicts a test system 400 for evaluating the aforementioneddesign and clinical considerations of the penetrating elements of thesystem 300, according to embodiments of the disclosed inventions. Thetest system 400 includes a load displacement apparatus 410, and a loadcell 420 fitted to a cross-head of the load displacement apparatus 410.The load cell 420 includes a connector 420A for affixing a penetratingelement 425 (e.g., elongate pusher member 310, delivery catheter 304,tissue penetrating member 306/250/350, shunt 200′) as shown in FIGS. 35,36, and 38. The connector 420A is sized and configured to fit and hold avariety of penetrating elements 425. A bath fixture 430 is coupled to ormounted on a heating platform 473; the heating platform 473 is coupledto or mounted on stage members 463A and 463B that control the locationof the bath fixture 430 relative to the load displacement apparatus 410in the X (463A) and Y (463B) planes. A tissue block 490 is disposedinside the bath fixture 430, and includes a tissue sample 486 (e.g.,human dura, pig dura, a dura surrogate such as Dura-Guard® dural repairpatch from Synovis Surgical Innovations, St. Paul, Minn.) clamped in thetissue block 490 for testing the penetrating element 425, as shown inFIGS. 35-38. Alternatively or additionally, an arachnoid tissue or asuitable surrogate for arachnoid layer 115 (e.g., human arachnoid, pigarachnoid, pig mesentery) can also be clamped in the tissue block 490for testing the penetrating element 425. The load displacement apparatus410 can control and vary the speed that penetrating element 425 advancestowards the tissue sample 486. The load cell 420 measures the forcesgenerated from the penetrating element 425 piercing tissue samples 486,as well as the forces generated when withdrawing the penetrating element425 from the pierced tissue sample 486.

As shown in FIG. 36, the tissue block 490 is coupled to a block stand474 disposed within the bath fixture 430. The tissue block 490 and blockstand 474 are rotatably coupled allowing an operator to adjust theorientation of the tissue block 490 relative to the block stand 474 andtherefore, relative to the piercing element 425, in the clockwise andcounterclockwise directions. The relative rotation of the tissue block490 and block stand 474 allows the operator to adjust and set a desiredangle for the penetrating element 425 to pierce or penetrate the tissuesample 486 clamped in the tissue block 490 when the load displacementapparatus 410 drives penetrating element 425 towards the clamped tissuesample 486 (piercing direction represented by arrow 425A in FIG. 36).

The tissue block 490 includes an upper plate 481 having a plurality ofchannels 484; the plate 481 is coupled to a lower support block 487, andthe lower support block 487 includes a connection port 483 (FIGS. 36 and37). The tissue sample 486 is clamped under the upper plate 481 and overthe lower support block 487 creating a chamber 488 between the sample486 and the support block 487, as shown in FIGS. 36 and 37. The lowersupport block 487 can be constructed using a clear material to observethe penetrating element 425 during testing (e.g., observe the extent oftissue deformation or whether arachnoid layer “tents” above the durasurrogate before piercing). The bath fixture 430 can be filled with atemperature controlled solution (e.g., saline) and/or the heating block473 can be used to control the temperature of the solution within thebath fixture 430. The chamber 488 of the tissue block 490 disposedwithin the bath fixture 430 can be pressurized with the temperaturecontrolled solution (or other CSF surrogate) via the port 483, such thatthe chamber 488 represents the subarachnoid space into which penetratingelement 425 will pierce during testing. The pressure of the CSFsurrogate in the chamber 488 can be controlled to create a differentialpressure between the CSF surrogate solution and the temperaturecontrolled solution in the bath fixture 430, which mimics the pressuredifferential between the subarachnoid space and venous system inpatients (e.g. 5-12 cm H20 for non-hydrocephalic patients).

FIG. 37 depicts the tissue sample 486 clamped between the upper plate481 and the lower support block 487 of the tissue block 490, accordingto the disclosed inventions. Screws 485 (or other suitable fasteners)secure the upper plate 481 to lower support block 487 clamping thetissue sample 486 between the upper plate 481 and the lower supportblock 487 to create the chamber 488. The upper plate 481 channels 484mimicking the IPS 102 (i.e., lumen) such that, the tissue sample 486represents the IPS wall 114 for testing the penetrating element 425 ofthe system 300. The channels 484 are configured to expose the clampedtissue sample 486 and allow contact with the penetrating element 425driven by the load displacement apparatus 410 in the piercing direction425A (FIG. 36). For example, FIG. 38 shows a tissue sample 486 and thepenetrating element 425 (e.g., beveled needle) oriented in the piercingdirection 425A to penetrate the tissue sample 486 at a 10-degreepenetration angle A₁.

Testing the penetrating element 425 having certain configurations, suchas shape (e.g., shape of the piercing tip, needle, beveled, or thelike), sizes (i.e., gauge number), and material (e.g., stainless steel,Nitinol, or the like) at various penetration speeds ranging from 0.1mm/s to 5 mm/s and various ranges of penetration angles using the testsystem 400 as previously described, yielded the exemplary datasummarized in FIG. 39. Of the penetrating element 425 tested, the datagenerally indicates that: (1) blunt needles require a higher force topenetrate dura mater, impose higher deformation on the tissue prior topuncture, and show a risk of coring the tissue during piercing duramater; (2) pencil tip and beveled needles show consistent retractionforces that translate to the best seal of the anastomotic connectionbetween the IPS 102 and CP angle cistern 138 (e.g., no CSF surrogateleaked between chamber 488 and bath fixture 430 up to a differentialpressure of 100 cm H20); and (3) Quincke and pencil tip needles requirethe least amount of force to puncture dura mater. While otherpenetrating elements 425 were evaluated and tested with test system 400,the test data showed that the quincke, pencil, and bevel shapepenetrating element 425 may be preferred for embodiments of thedisclosed inventions based on the relatively low tissue penetrationforce require to pierce dura mater, minimal tissue damage caused duringtissue penetration, the sealing characteristics of the penetration tractthrough the tissue, minimal tissue deformation during penetration, andminimal additional support requirements of the penetrating element 425to prevent buckling or bending during penetration.

Methods can be used to assess the patency of the shunt 200 or 200′(e.g., of lumen 207 and valve 209) after deployment and implantation ofthe shunt 200 or 200′, according to embodiments of the disclosedinventions. In one exemplary method of accessing the patency of theimplanted shunt 200 or 200′, with reference to FIG. 40, a clinician caninject an iodinated contrast agent into the lumbar thecal sac of thepatient by a lumbar puncture or spinal tap 500. After the injection step500 (e.g., approximately five to ten minutes after 500), the contrastagent will disperse from the lumbar subarachnoid space into the CSF inthe intracranial subarachnoid space around the brain stem from thecirculation of CSF within the subarachnoid space. Using one or more ofthe imaging methods previously described herein, the presence ofcontrast agent in the CSF will be apparent by the clinician (e.g.,highlight in an imaging system) 510. If the imaging step 510, detectsthe presence of contrast agent 520 throughout shunt lumen 207 and/or inthe venous system immediately adjacent the proximal portion 204 of theshunt 200, then shunt 200 is patent (i.e., not occluded) 530, asevidenced by the contrast agent dispersing from the flow of CSF in theCP angle cistern through the shunt 200. If the imaging step 530 does notdetect the presence of contrast agent throughout shunt lumen 207 and/orin the venous system immediately adjacent the proximal portion 204 ofthe shunt 200, then shunt 200 is not patent (i.e., occluded) 540.Additionally, during the lumbar puncture step 500, a CSF pressuremeasurement can be obtained 550. A pressure measurement within normalranges further confirms that the deployed shunt 200 is draining CSF fromthe intracranial subarachnoid space into the venous system, and apressure measurement higher than the normal ranges further confirms thatthe deployed shunt 200 is or may be occluded.

In another exemplary method of assessing the patency of the implantedshunt 200 or 200′, with reference to FIG. 41, a clinician can evaluateCSF flow through the deployed shunt 200 or 200′ by injecting 600radioactive or neutron-activated microspheres (e.g., microspheres fromBioPAL, Worcester, Mass.) into the CSF via a lumbar puncture or byaccessing the subdural space in the cranium. Microspheres with adiameter of 15 microns or larger would not pass through the arachnoidgranulations, which absorb CSF from the subarachnoid space into thevenous system, yet should be selected such that the microspheres canpass through lumen 207 of a deployed shunt (e.g., having a diameterranging from 0.1 mm to 2 mm). Assuming a properly functioning deployedshunt 200 according to the disclosed inventions, the presence ofmicrospheres in the CSF would only enter the blood stream via a patentshunt 200; a venous blood sample or tissue sample from the lungs can becollected and assessed for the presence of microspheres 610. The numberof microspheres obtained via a venous sampling at various points in timereflects the flow rate through the shunt 200 and the number ofmicrospheres injected into the CSF 620. Samples obtained via a biopsy oflung tissue are also proportional to the total flow of microspheresthrough the shunt and the number of microsphere injected into the CSF.Collected samples without any microspheres suggest that CSF is notflowing through the deployed shunt 200, and the shunt 200 is occluded630. For example, the venous blood sample can be obtained from the guideor delivery catheter in the vasculature for shunt deployment and within15 to 20 minutes of injecting microspheres into the CSF. This samplingtechnique can provide a sensitive measurement of the CSF flow throughthe shunt 200 if assessed by radioactive or neutron-activatedmicrospheres because it maximizes the collection of microspheres flowingthrough the shunt 200. The neutron activated microsphere assay isextremely sensitive with the limits of detection almost down to 1microsphere. Venous blood or lung tissue samples can be sent to acommercial testing service, such as BioPAL, that uses neutron activationtechnology to measure the microsphere content of the sample.

FIGS. 43A-D illustrate an alternative delivery catheter 304′ fordelivering the shunt 200 into a target site of a patient, constructed inaccordance with embodiments of the disclosed inventions. For ease inillustration, the features, functions, and configurations of thedelivery catheter 304′ that are the same as in the assembly 300 of FIGS.3B and 4A-D and/or are the same as in the assembly 300′ of FIGS. 5A-Jare given the same reference numerals. The delivery catheter 304′ isdimensioned to reach remote locations of the vasculature and isconfigured to deliver the shunt 200 percutaneously to the targetlocation (e.g., inferior petrosal sinus). The delivery catheter 304′ maycomprise variable stiffness sections (e.g., varying ratio of material,including selective reinforcement, such as braids, coils, or the like)suitable to provide sufficient “pushability” and “torqueability” toallow the catheter 304′ to be inserted, advanced and/or rotated in thevasculature to position the distal portion 344 of the catheter at thetarget site within the IPS 102. Further, the distal portion 344 shouldhave sufficient flexibility so that it can track and maneuver into thetarget site. Variable stiffness in the catheter 304′ is achieved, forexample, by locally varying the properties or distribution of thematerials used and/or varying the durometer or thickness of thematerials during the process of manufacturing. By way of non-limitingexamples, the materials used in manufacturing the catheter 304′ mayinclude polyether block amide (Pebax®) and Nylon. Other suitablematerials that may be contemplated for making the catheter 304′ includehomopolymers, copolymers or polymer blends containing polyamides,polyurethanes, silicones, polyolefins (e.g., polypropylenes,polyethylenes), fluoropolymers (e.g., FEP, TFE, PTFE, ETFE),polycarbonates, polyethers, PEEK, PVC, and other polymer resins knownfor use in the manufacture of catheters. It should be appreciated thatwhen appropriate, the delivery catheter 304′ may be used in combinationwith the delivery assembly 300/300′ previously described.

The delivery catheter 304′ comprises a tissue penetrating member 350coupled to the distal portion 344 of the catheter 304′. The tissuepenetrating member 350 comprises a tubular configuration having a lumen355 fluidly coupled to the lumen 305 of the delivery catheter 304′ (FIG.43C), which allows the shunt 200 (i.e., slidably disposed in the lumen305 of the catheter 304′) to be deployed into the target site when theanastomosis channel 140 is created (not shown). The tissue penetratingmember 350 comprises a piercing edge 351 and a piercing tip 352 (FIGS.43A, 43C-D), which will be described in further detail below. It shouldbe appreciated that when using the delivery catheter 304′ to deliver anddeploy the shunt 200 into the target site, the tissue penetratingelement 306 of the delivery assembly 300 and/or the tissue penetratingmember 250 incorporated in the shunt 200′ may not be required.

The delivery catheter 304′ further comprises an expandable element 390coupled to, or disposed on the distal portion 344 of the deliverycatheter 304′. The expandable element 390 is proximately disposed to thepiercing tip 352 of the tissue penetrating member 350, as to driveand/or advance the tissue penetrating member 350 into the IPS wall 114to create anastomosis between the IPS 102 and the CP angled cistern 138(FIG. 44C). The expandable element 390 may comprise an expandableballoon, foam, stent, or combinations thereof. In the embodiments ofFIGS. 43A-44C, the expandable element 390 is an expandable balloon. Theexpandable element 390 comprises a collapsed configuration (i.e.,deflated, as shown in FIGS. 43A-D and 44A), a first expandedconfiguration (e.g., partially inflated or first expanded state, asshown in FIG. 44B), and a second expanded configuration (i.e., inflatedor second expanded state, as shown in FIG. 44C). It will be appreciatedthat the expandable element 390 provides an off-axis expandedconfiguration (FIGS. 44B-C). In other embodiments, the expandableelement 390 may include any suitable expandable configuration, such as,a conical, tapered, accordion-like, angled configurations, orcombinations thereof.

The expandable element 390, when expanded/inflated to the first expandedstate, the expandable element 390 causes the tip of the tissuepenetrating element 350 to engage the dura matter of the IPS wall 114,and thereafter inflated to the second expanded state causes the tissuepenetrating element 350 and tip to penetrate through the IPS wall 114and arachnoid layer 115, respectively, into the CP angle cistern 138, asshown in FIGS. 44B-E. Further, when the expandable element 390 isexpanded/inflated to the first expanded state, the element 390 orientsthe tissue penetrating member 350 towards the IPS wall 114 and initiatestissue engagement as shown in FIG. 44B thereby locking delivery catheter304′ in the IPS 102 relative to the target penetration site in the IPSwall 114. By way of example, the height of the bulb portion ofexpandable element 390 expandable element 390 (e.g., inflation/volume ofan interior cavity 391 of the expandable element 390 expandable element390) in its first expanded state shown in FIG. 44B, as measured from IPSwall 117, can be between 0.5 mm to 2.5 mm (e.g., 1.5 mm). Additionalexpansion/inflation of expandable element 390 expandable element 390from its first expanded configuration to its second expandedconfiguration advances the tissue penetrating member 350 through the IPSwall 114 as shown in FIG. 44C. Again, by way of example, the height ofthe bulb portion of expandable element 390 expandable element 390 (e.g.,inflation/volume of the balloon's interior 391) in its second expandedstate shown in FIG. 44C, as measured from IPS wall 117, can be between2.5 mm to 4.0 mm (e.g., 3.0 mm). It should be appreciated that theheight of the bulb portion of expandable element 390 may also be smallerthan 2.5 mm in patients with smaller diameter IPS 102, or larger than4.0 mm in patients with larger diameter IPS 102.

Additionally, while the expandable element 390 is beingexpanded/inflated to transition from the deflated configuration (FIG.44A) to the partially inflated configuration (FIG. 44B), and into thefully inflated configuration (FIG. 44C), the tissue penetrating member350 transitions from being disposed substantially parallel relative tothe IPS wall 114 (FIG. 44A) into being disposed in angles of interactionrelative to the IPS wall 114 (FIGS. 44B-C). The angles of interaction ofthe tissue penetrating member 350 from the delivery configuration mayvary from approximately 0° to approximately 150° relative to the IPSwall 114, preferably from approximately 5° to approximately 90°.

The delivery catheter 304′ further comprises an inflation lumen 309fluidly coupled to the interior 391 of the expandable element 390 (FIGS.43B-C), and to a source of inflation media (not shown) for supplyingfluid and/or gas to selectively inflate and deflate the expandableelement 390. For example, the inflation media source may have apredetermined volume of fluid/gas to adequately inflate the expandableelement 390 causing the advancement of the tissue penetrating member 350into the IPS wall 114. Additionally, the source of inflation media mayinclude aspiration means to deflate the expandable element 390 bywithdrawing the fluid/gas from the expandable element 390. The inflationmedia source may optionally include a pressure sensor to measure theinflation pressure to ensure adequate inflation without over inflationof the expandable element 390. The expandable element 390 may beinflated with one or more fluids (e.g., saline, contrast agent, or thelike) or with gas (e.g., air), and/or a combination thereof. Forexample, the expandable element 390 may be inflated with a mixture ofsaline and contrast agent (i.e., fluid containing radio-opaquematerials) for purposes of imaging, according to the disclosedinventions (e.g., mixture comprising 50% saline and 50% contrast agent).

The expandable element 390 coupled to the delivery catheter 304′ may bemade of or otherwise include compliant, semi-compliant, or non-compliantpolymeric materials, such as silicone, urethane polymer, thermoplasticelastomer rubber, santoprene, nylon, polytetrafluoroethylene “PTFE”,polyethylene terephthalate “PET”, and other suitable materials orcombinations thereof. In embodiments comprising compliant materials, theexpandable element 390 is preferably composed of urethanes (e.g.,Pellethane or Chronoprene).

In another embodiment, the expandable element 390 is composed of anon-compliant material, such as polyurethane terephthalate “PET”, whichallows and facilitates inflation of the expandable element 390 by asource of inflation media filled with a predetermined volume offluid/gas. The predetermined volume of fluid/gas may correspond to, forexample, a preformed volume of the expandable element 390, which will bedescribed in further detail below. Having a source of inflation mediafilled with a predetermined volume of fluid to inflate the noncompliantmaterial of expandable element 390 reduces the risk of overinflating andoverextending of the expandable element 390 in its deployedconfiguration. Additionally, the expandable element 390 composed ofnon-compliant material is configured to withstand higher inflationpressure without deforming or overextending, as compared to balloonscomposed of compliant materials.

FIGS. 44A-C illustrate a method for creating anastomosis via anendovascular approach to deliver and implant the shunt 200 into thetarget site using the delivery catheter 304′, in accordance withembodiments of the disclosed inventions. The distal portion 344 of thedelivery catheter 304′ having the tissue penetrating member 350 in adelivery orientation, and the expandable element 390 in the collapsedconfiguration, is advanced into the target site within the IPS 102, asshown in FIG. 44A. Prior to the piercing of the IPS wall 114 and thearachnoid layer 115 to create anastomosis and access the CP anglecistern 138, proper orientation of the distal portion 344 of thedelivery catheter 304′, particularly, proper orientation of the tissuepenetrating member 350 and the expandable element 390, may be verifiedprior to actuation according to the imaging methods previouslydisclosed. For example, markers may be used for positioning andorienting the distal portion 344 of the delivery catheter 304′. Whenneeded, the positioning and orientation of the tissue penetrating member350 and the expandable element 390 disposed on the distal portion 344 ofthe delivery catheter 304′ may be adjusted, for example, by applying arotational force directly to the body of the delivery catheter 304′.

Once proper positioning and orientation of the distal portion 344 of thedelivery catheter 304′ is achieved, the expandable element 390 isinflated transitioning into its partially expanded configuration andbending the distal portion 344 of delivery catheter 304′ away from IPSwall 117 so as to orient the tissue penetrating member 350 into the IPSwall 114 at a suitable angle, as shown in FIG. 44B. Continuing inflationuntil the expandable element 390 reaches its fully expandedconfiguration advances the tissue penetrating member 350 causingpiercing and penetration of IPS wall 114, and penetration through thearachnoid layer 115 until reaching the CSF-filled subarachnoid space 116and/or the CP angle cistern 138 creating the anastomosis channel 140, asshown in FIG. 44C. Simultaneously or consecutively with the creation ofthe anastomosis channel 140, the shunt 200 is advanced, deployed andimplanted at the target site, as previously described. Once the shunt200 is implanted, the balloon 290 is deflated-preferably after thedeployment of the distal anchoring mechanism 229 of shunt 200- and thedelivery catheter 304′ is withdrawn out of the patient (not shown). Asillustrated in FIGS. 44A-C, expansion of expandable element 390 insidethe lumen of IPS 102 limits the penetration depth of tissue penetratingmember 350 into CP angle cistern 138; that is, the configuration ofexpandable element 390 and the anatomical confines from the lumen of IPS102 and IPS wall 114 prevent expandable element 390 in its expandedconfiguration, from further expansion that could advance the coupledtissue penetrating member 350 too far distally into the subarachnoidspace 116 and/or the CP angle cistern 138. The penetration depth limitillustrated in FIGS. 44C and 44E, in turn, maintains adequate space inCP angle cistern 138 between arachnoid layer 115 and brain stem 112 (notshown) or expansion envelope for a distal portion of the shunt and/ordistal anchoring mechanism to deploy in the subarachnoid space withoutdamage critical anatomical structures.

FIGS. 44A-C depict tissue penetrating member 350 as it transitionsthrough a 90-degree turn (e.g., in a range of 30 degrees to 90 degrees)from its delivery orientation (i.e., coaxial with the longitudinal axisof delivery catheter 304′ and IPS lumen 102) to a fully penetratedorientation (i.e., orthogonal to IPS wall 114) as expandable element 390transitions to a fully expanded configuration. For illustrationpurposes, FIGS. 440-E are perspective views of FIGS. 44B-C respectively,depicting a top-side view of the tissue penetrating member 350transitioning into an expanded configuration which facilitates fullpenetration of the IPS wall 114 and arachnoid layer 115 into the CPangle cistern 138. The narrow diameter and/or tortuous pathway of theIPS lumen may not allow tissue penetrating member 350 to penetrateorthogonal to IPS wall 114 in all patients; thus, the tissue penetratingmember 350 may only transition through about a 30-degree turn to70-degree turn while expandable element 390 expands before completelypenetrating IPS wall 114. For example, the clinician may expandexpandable element 390 to a first expanded state where penetratingelement 350 engages the dura of IPS wall 114 at an angle of about 45degrees or less, without fully penetrating into the CP angle cistern138, as shown in FIG. 44B. At this step, the clinician can confirm thetrajectory of the penetrating element 350 (e.g., using one or more ofthe imaging methods described herein) before completing the penetrationstep of the procedure. If unsatisfied with the trajectory presented, theclinician can deflate expandable element 390 to its collapsed ordelivery configuration, adjust the position or orientation of deliverycatheter 304′, and re-expand expandable element 390 to a first expandedconfiguration where penetrating element 350 engages IPS wall 114 on asuitable trajectory for further penetration through the IPS wall into CPangle cistern 138. Thereafter, the clinician can further expandexpandable element 390 until the penetrating element 305 has completelypenetrated through the IPS wall 114 and arachnoid layer 115 underlyingthe CP angle cistern 138. (e.g., at an angle of about 70 degrees).

Additionally to the method for creating anastomosis 140 via anendovascular approach of FIGS. 44A-C, a clinician may apply a suitablemechanical force to the delivery catheter 304′ further assisting withthe advancement of tissue penetrating member 350 driven by theexpandable element 390 into the IPS wall 114.

Additionally to the expandable element 390 disclosed above, deliverycatheter 304′ may include a second expandable balloon, foam, stent, orcombination thereof, located proximally from the distal end of thecatheter (e.g., about 1 cm to about 3 cm from the distal end of thecatheter). The second expandable member (not shown), when expanded froma collapsed to expanded configuration, further secures delivery catheter304′ about the target penetration site in IPS wall 114. In embodimentswhere the second expandable member is a balloon, the balloon can becomposed of non-compliant or compliant materials and communicate fluidlywith inflation lumen 309 or a similar yet fluidly distinct lumen.Further, the second balloon can be configured within the dimensionalranges previously disclosed with respect to expandable element 390. Thesecond expandable member can extend circumferentially around theexterior of the delivery catheter or may comprise a smaller portion ofthe delivery catheter circumference (e.g., approximately 25%,approximately 50%, approximately 75%). In embodiments where the secondexpandable member comprises a smaller portion of the delivery cathetercircumference, such expandable member can be located on the oppositeside of delivery catheter 304′ when compared to the expandable element390 or, alternatively, on the same side of delivery catheter 304′ as theexpandable element 390, or in some relative clocking between fullyaligned and fully opposed orientations.

In some embodiments, deploying the shunt 200 comprises advancing thedistal portion 202 of the shunt 200 from the IPS 102 into the CP anglecistern 138 using the tissue penetrating member 350. The tissuepenetrating member 350 may be coupled to a distal portion 202 of theshunt 200, so that advancing the distal portion 202 of the shunt 200from the IPS 102 into the CP angle cistern 138 comprises advancing thetissue penetrating member 350 and distal portion 202 of the shunt 200′through the dura mater tissue wall of the IPS 114, and through thearachnoid tissue layer 115, respectively, into the CP angle cistern 138.During advancement of the distal portion 202 of the shunt 200, thedistal portion 202 of the shunt 200 is at least partially disposed inthe delivery lumen 305 of the delivery catheter 304′, the tissuepenetrating member 350 comprising a tissue penetrating tip of thedelivery catheter 304′, and where advancing the distal portion 202 ofthe shunt 200 from the IPS 102 into the CP angle cistern 138 comprisesadvancing the delivery catheter 304 so that the tissue penetrating tippenetrates through the dura mater tissue wall of the IPS 114, andthrough the arachnoid tissue layer 115, respectively, into the CP anglecistern 138. The delivery catheter 304′ distal portion 344 assumes acurved configuration that guides the tissue penetrating tip into contactwith the dura mater of the IPS 114 at an angle in a range of 30 degreesto 90 degrees, as shown in FIGS. 44B-C. As shown in FIGS. 44A-E, thedistal portion 344 of the delivery catheter 304′ comprises theexpandable element 390 (or wall portion that is expanded) to cause thedistal portion of the delivery catheter 304′ to assume the curvedconfiguration. The delivery catheter 304′ comprising one or moreradiopaque markers located and dimensioned to indicate a position andorientation of the distal portion 344 of the delivery catheter when inthe curved configuration. Deploying the shunt 200 further compriseswithdrawing the distal portion of the delivery catheter 304′ from the CPangle cistern 138, while maintaining the distal portion 202 of the shunt200 at least partially disposed in the CP angle cistern 138.

FIGS. 45A-D illustrate an exemplary tissue penetrating member 350constructed according to embodiments of the disclosed inventions. Thetissue penetrating member 350 comprises a tubular configuration having aproximal end portion 353 and a distal end portion 357, and lumen 355extending therebetween (FIG. 45B). The distal end portion 357 of thetissue penetrating member 350 comprises a tapered/beveled piercing edge351 that terminates in the piercing tip 352 (FIGS. 45A-B). FIGS. 45D and46G illustrate exemplary dimensions (in inches), angles and propertiesof the tissue penetrating member 350, which are not intended to limitthe embodiment of FIGS. 45A-C.

FIGS. 46A-G illustrate other exemplary piercing elements 350 constructedaccording to embodiments of the disclosed inventions. The proximal endportion 353 of tissue penetrating member 350 further extends (FIGS.46E-F) or it is coupled to an elongated tubular member 359 (FIGS.46A-D). The elongated tubular member 359 comprises a smaller outerdiameter and profile than the outer diameter and profile of the proximalend portion 353 of the tissue penetrating member 350 (FIGS. 46A-D). Theelongated tubular member 359 of FIGS. 46A-D and the extending proximalportion 353 of FIGS. 46E-F are shaped and dimensioned to be disposedwithin the lumen 305 of the distal portion 344 of the delivery catheter304′. The tissue penetrating member 350 embodiment shown in FIGS. 46E-Fincludes cut portions along the length of the tubular member 359 shownas a spiral cut pattern in FIGS. 46E-F. The cut portions advantageouslyprovide sufficient flexibility for the penetrating element, for example,to bend from a delivery to expanded configuration if incorporated intothe expandable element 390 embodiment shown in FIGS. 43, 44, and 47,while maintaining sufficient column strength of the tissue penetratingmember 350 to penetrate through dura and arachnoid tissues. In theembodiments of FIGS. 46A-D, the outer diameter and profile of tissuepenetrating member 350 may match the outer diameter and profile of thedistal portion 344 of the delivery catheter 304′.

It should be appreciated that the dimensions, angles and properties ofthe tissue penetrating member 350 of FIGS. 45A-46D may be incorporatedinto the tissue penetrating element 306 of the delivery assembly 300and/or the tissue penetrating member 250 of the shunt 200′.

FIGS. 47A-49C illustrate expandable expandable element 390 constructedaccording to various embodiments of the disclosed inventions. Theexpandable expandable element 390 is shown in a preformed moldedconfiguration (FIGS. 47A, 48A and 49A) before it is mounted on orcoupled to the distal portion 344 of the delivery catheter 304′. Theexpandable element 390 includes a first-end portion 392 (e.g.,proximal), a middle-body portion 393 (e.g., expandable) and a second-endportion 394 (e.g., distal), collectively defining an interior 391 of theexpandable element 390 through which the delivery catheter 304′ or othertype of elongate structure extends. The first-end portion 392 andsecond-end portion 394 of the expandable element 390 may includerespective tubular or other suitable configurations to be coupled to thedistal portion 344 of the delivery catheter 304′ by adhesive, thermalbonding or the like, interlocking geometries, mechanical fastening,sutures or combinations thereof.

In comparison to the expandable expandable element 390 embodiment ofFIG. 47A-C where a shunt is delivered through a lumen of the expandableelement 390, the balloon embodiments of FIGS. 48A-D, 49A-D, when in anexpanded configuration, provide a ramp to deflect a penetrating element306 of the elongate pusher member 310, penetrating element 250 of theshunt 200′ or penetrating element 350 of the delivery catheter 304′toward IPS wall 114, similar to the deflecting element 370 coupled to ordisposed on the distal portion 344 of the delivery catheter 304described in connection with FIGS. 20A-F. In an expanded configuration,the transition from first-end portion 392 to middle-body portion 393 ofthe expandable element 390 of FIGS. 48A-D, 49A-D deflects the piercingelement away from the central axis of the delivery catheter to penetrateIPS wall 114. That is, the piercing element or a sheath housing thepiercing element can emerge from delivery catheter 304 at a locationproximal to first-end portion 392 of the balloon; as the piercingelement advances distally; the transitioned portion of the inflatedballoon directs the piercing element into the tissue of IPS wall 114(FIGS. 48D and 49D). As described herein, the piercing element used withthe balloon embodiments of FIGS. 48A-D, 49A-D can be configured suchthat the shunt is delivered through a lumen of the piercing element orsuch that the piercing element extends through the shunt lumen to deploythe shunt distal end (e.g., anchor 229) within the CP angle cistern.

The expandable element 390 may be composed of material previouslydescribed that may have a shore durometer range between 40 A to 90 A,and/or a shore durometer range between 25 A to 100 A. For example, theexpandable element 390 may be manufactured with standard processingequipment to obtain a molded balloon having a wall thickness ofapproximately between 0.00025 inches (0.00635 mm) to 0.003 inches(0.0762 mm) in the middle expandable portion 393. Further, the wallthickness of the expandable element 390 may vary from thicker, in andaround the first-end portion 392 and in and around the second-endportion 394 to thinner in and around the a middle-body portion 393 atleast. For example, the first-end portion 392 may have a wall thicknessgreater than a wall thickness of the middle-body portion 393.

Portions 392, 393, and/or 394 of expandable element 390 can have anon-uniform thickness. For the expandable element 390 embodiment shownin FIGS. 43, 44, 47 and with reference to FIG. 47, a central region ofmiddle portion 393 comprises a thicker wall thickness than the first andsecond end regions of middle portion 393; the localized thinning ofexpandable element 390 at the end regions of middle portion 393 providesthe eccentric expansion of expandable element 390 depicted in FIGS.43-44. In some embodiments of expandable element 390, the central regionof middle portion 393 comprises the thickest portion of expandableelement 390.

In embodiments of the invention and with the use of standard blow and/ordip molding principles, an angled (FIGS. 47A-C), an off-axis (FIGS.44A-E, 48A-C), or a conical molded configuration (FIGS. 49A-C) of theexpandable element 390 may be manufactured. By way of example, theexpandable element 390 can have a variety of shapes in the molded,mounted or inflated configurations, including but not limited to:diamond, circular, oval, multi-sided, or irregular shapes, and/or anglesthat are adapted to orient and advance the tissue penetrating member 350into the IPS wall 114 and arachnoid layer 115 to create the anastomosischannel 140, as previously described. For example, FIGS. 50A-B depict astraight mounted configuration of the expandable element 390, in whichFIG. 50A shows the collapsed configuration and FIG. 50B shows theexpanded configuration of the expandable element 390. In addition,penetrating element 350 can be folded further inward than as depicted inFIG. 50A, proximally along the length of expandable element 390 suchthat the tip of penetrating element 350 does not extend past or emergefrom the distal end of expandable element 390 in a collapsed or deliveryconfiguration. As the balloon is inflated, the length of expandableelement 390 unfurls causing penetrating element 350 to emerge from theinfolded balloon to its expanded configuration shown in FIG. 50B.

FIGS. 47A-50B illustrate exemplary dimensions, angles and properties ofthe expandable element 390, which are not intended to limit theembodiments of expandable element 390. FIG. 47D illustrates exemplarytabulated material properties of the expandable element 390 depicted in47A-C, which are not intended to limit the embodiment of FIGS. 47A-C.

FIGS. 51A-54C illustrate further exemplary piercing elements forcreating anastomosis via the endovascular approach, constructed inaccordance with embodiments of the disclosed inventions. The tissuepenetrating member 250 comprises a stylet (i.e., solid elongated elementwith a piercing distal tip), as shown in FIGS. 51A-54C. Alternatively,the tissue penetrating member 250 may comprise a needle (i.e., hollowtubular element with a piercing distal tip), as shown in FIGS. 45A-46D,which may be incorporated and/or detachably coupled to the shunt 200′,previously described. The tissue penetrating member 250 furthercomprises a proximal portion 258, an elongated body portion 252, and adistal portion 255 that terminates in a distal tip 255′. The distal endtip 255 is configured for piercing the IPS wall 114 and arachnoid layer114 and creating the anastomosis channel 140, as shown, for example inFIGS. 5C-J. Embodiments of the tissue penetrating member 250 of FIGS.51A-54C can be incorporated into the distal end of the various deliveryassembly 300 or delivery catheter 304 embodiments disclosed herein.

The distal portions 255 of the tissue penetrating member 250 of FIG. 51Aand FIG. 53A terminate in a straight point distal tips 255′. FIGS. 51B,52B, 53B and 54B are cross-section views of a portion of tissuepenetrating member 250 along the respective axis B-B shown in FIGS. 51A,52A, 53A and 54A. The diameter of the tissue penetrating member 250,along the distal portion 255 and/or elongated body 252 can range fromapproximately 0.006 inches (0.1524 mm) to 0.030 inches (0.762 mm). Itshould be appreciated that other suitable diameters of the tissuepenetrating member 250 may be provided, as long as the shunt 200 and thedelivery assembly 300 accommodate the dimensions of the tissuepenetrating member 250. FIG. 51C and FIG. 53C depict a perspective viewof the distal portion 255 of tissue penetrating member 250 having thestraight point distal tips 255′. Alternatively, the distal portions 255of the tissue penetrating member 250 of FIG. 52A and FIG. 54A terminatesin a rounded distal tip 255′ (e.g., bullet-nose, ellipticalcross-section, blunt configuration). The cross-sectional views of thetissue penetrating member 250 in FIG. 52C and FIG. 54C depict exemplaryelliptical curvatures of the rounded distal tips 255′.

Further, the tissue penetrating member 250 may comprise a neck portion257 proximately disposed to the distal portion 255, as shown in FIGS.53A, 53C and FIGS. 54A, 54C. The neck portion 257 comprises a smallerouter diameter relative to the elongated body 252 and distal portion 255of the tissue penetrating member 250. The outer diameter of the neckportion 257 can be, for example, approximately 25% to 75% smaller thanthe outer diameter of the elongated body 252 and distal portion 255 ofthe tissue penetrating member 250. The neck portion 257 provides arecess in the tissue penetrating member 250 for the distal portion 202and/or the distal anchoring mechanism 229 of the shunt 200/200′ toreside in a delivery configuration as the tissue penetrating member 250passes through the IPS wall 114. The distal portion shunt 200 isdetachably coupled to neck portion 257 of the tissue penetrating member250 200′, and once the anastomosis channel 140 is created, the shunt200′ implanted in the target site (e.g., as shown in FIGS. 5H-J).

In some embodiments, the tissue penetrating member 250 may have a moreabrupt transition between the distal portion 255 of the tissuepenetrating member 250 and the neck portion 257, compared to thetransition of the elongated body portion 252 of the tissue penetratingmember 250 and the neck portion 257, as shown in FIGS. 53A and 54A.These transitions or curved profile of neck portion 257 (e.g., as shownin FIGS. 53A, 53C, 54A, and 54C) facilitate the delivery of shunt 200through IPS wall 114 in a collapsed or delivery configuration.Optionally, an outer sheath (not shown) can be used to hold shunt 200over the tissue penetrating member 250 in a delivery configuration asthe tissue penetrating member 250 and shunt 200 are advanced through thepatient's vasculature. For example, the distal end of the sheathcovering the shunt disposed over the piercing element can be advanced tothe target penetration site in IPS wall 114 such that the distal end ofthe sheath abuts, but does not pass through, the IPS wall 114 as tissuepenetrating member 250 and the shunt 200 penetrate the IPS wall 114 andthe arachnoid layer 115 into CP angle cistern 138.

In other embodiments, the proximal portion 258 and/or the elongated bodyportion 252 of the tissue penetrating member 250 can have a greaterouter diameter than distal portion 255 of tissue penetrating member 250(e.g., an outer diameter of approximately 25% to 75% greater than theouter diameter of body or distal portions of the piercing element). Theincreased outer diameter of the proximal portion 258 and/or theelongated body portion 252 of the tissue penetrating member 250 preventsthe shunt 200 from sliding proximally over the tissue penetrating member250 during navigation through the patient's vasculature and thepenetration step, and serves as a penetration stop by preventing thetissue penetrating member 250 (and accompanying delivery system) frompassing beyond IPS wall 114 and arachnoid layer 115 into thesubarachnoid space 116. Once a distal portion of shunt 200 and/or distalanchoring mechanism 229 has been deployed in CP angle cistern 138, thetissue penetrating member 250 can be withdrawn from the shunt lumen 207,delivery assembly 300.

In some embodiments, the tissue penetrating member 250 may be coupled toan energy source (not shown) to facilitate the piercing and/oradvancement through the IPS wall 114 and arachnoid layer 115 thatseparates the lumen of IPS 102 from the subarachnoid space 116/CP anglecistern 138. The energy source can provide one or more energy types,including, but not limited to, radio frequency energy (RF), thermalenergy, acoustic energy or the like. For example, the piercing elements250 of FIGS. 51A-54C, particularly, the piercing elements 250 having thebullet-nose tip 255′ of FIGS. 52A, 52C and FIG. 54A, 54C may be coupledto a source of high frequency RF energy to assist with the advancementthrough the IPS wall 114 and arachnoid layer 115 to create anastomosis140 between IPS 102 and CP angle cistern 138. The use of RF energy inthe piercing elements 250 coagulates tissue while creating theanastomosis channel 140 thereby eliminating or reducing bleeding intothe subarachnoid space, and can eliminate the need for a sharpenedpenetrating element facing brainstem 112 after passing through the IPSwall 114 and arachnoid layer 115 into the CP angle cistern 138.

By way of non-limiting example, the tissue penetrating member 250 ofFIGS. 51A, 51C that includes the straight point distal tip 255′ fordelivering RF energy to penetrate the IPS wall 114 and arachnoid layer115. The straight point distal tip 255′ can focus the RF energy at thedistal most point of tissue penetrating member 250 to facilitatepenetrating through the IPS wall 114 and arachnoid layer 115, withoutdispersing electrical current to nearby tissue or structures. Thegradual transition from straight point distal tip 255′ to distal portion255 of the tissue penetrating member 250 gently dilates the tissue ofIPS wall 114 during the penetration step to minimize tissue damageduring the delivery and deployment of shunt at the target site. In someembodiments, the tissue penetrating member 250 of FIGS. 51A-54C isconfigured to pass through shunt lumen 207 of the various embodiments ofshunt 200 disclosed herein such that the shunt can be delivered throughthe IPS wall 114 as the tissue penetrating member 250 penetrates throughthe IPS wall 114 and arachnoid layer 115 into CP angle cistern 138.

The tissue penetrating member 250 of FIGS. 51A-54C can be made fromNitinol or other conductive materials. The tissue penetrating member 250can be a straight, rigid piece of material incorporated into the distalend of a delivery catheter 304 or other element of delivery assembly300. Alternatively, the tissue penetrating member 250 can be primarilyflexible, similar to flexible micro guide wires known in the art. Shunt200 disposed over a flexible tissue penetrating member 250 can providesufficient column strength to the combination of the shunt/piercingelement, which allows navigation through the patient's vasculature, tothe target penetration site in IPS wall 114, and into CP angle cistern138. The flexible configuration of tissue penetrating member 250provides additional safety if the tissue penetrating member 250 advancestoo far distally into the cistern 138; the floppy, guide wire-likeconfiguration further reduces the risk that the tissue penetratingmember 250 will damage local critical structures such as the brain stemor cranial nerves.

The tissue penetrating member 250 of FIGS. 51A-54C and delivery assembly300 can be configured for use with an electrosurgical unit thatgenerates and supplies RF energy to the distal tip of tissue penetratingmember 250. Several manufacturers and distributors provideelectrosurgical units suitable for use with embodiments of the disclosedinventions (e.g., Aaron® Product Line, Bovie Medical Corporation,Clearwater, Fla.). As will be appreciated by those of skill in the art,all but the distal most portion of the tissue penetrating member 250(e.g., distal most 1 mm to 15 mm) may be insulated such that only thedistal tip 255′ or distal portion 255 of the tissue penetrating member250 delivers RF energy to IPS wall 114 (and not the delivery assembly300 and/or delivery catheter 304). Standard electrosurgical unitsprovide multiple settings that can optimize the use of such systems foruse with the disclosed embodiments. For example, monopolar versusbipolar operation focuses the RF energy around a pinpoint penetrationsite from the distal tip 255′ and/or distal portion 255 of tissuepenetrating member 250 in IPS wall 114, without damaging nearby tissueor structures. Coagulation and/or blended settings, as opposed to purecut, can further pinpoint the RF energy to the contact point between thedistal tip 255′ and/or distal portion 255 of the tissue penetratingmember 250 and IPS wall 114 without generating excess heat andvaporizing cells. Such coagulation or blended settings advantageouslyprovide a controlled delivery of RF energy to pass the tissuepenetrating member 250 through the target penetration site, withoutdispersing RF energy to the surrounding tissues, while also coagulatingthe tissue to prevent localized bleeding from IPS wall 114. Adjustablepower settings allow for further optimization of electrosurgical unitswith the disclosed embodiments. For example, with a coagulation setting,a power setting from about 5 watts to about 20 watts, and preferablyfrom about 8 watts to about 12 watts, can be used with tissuepenetrating member 250 to penetrate from IPS 102 into CP angle cistern138. In addition, an electrosurgical unit can be configured to stop thedelivery of RF energy to the tissue penetrating member 250 upondetecting a change in impedance; a detector on the tissue penetratingmember 250 can provide impedance feedback to the electrosurgical unit todifferentiate between dura mater and CSF as the distal tip 255′ of thetissue penetrating member 250 emerges from the IPS wall 114 andarachnoid layer 114 into the CSF-filled subarachnoid space 116 and/or CPangle cistern 138.

FIGS. 55A-E illustrate an exemplary elongated portion 203 of the shunt200, according to embodiments of the disclosed inventions. As describedabove, the shunt 200 includes the proximal portion 204, the distalportion 202, and the elongate body 203 extending therebetween. The shunt200 further includes lumen 207 extending from the proximal opening 205to the distal opening 201 of the shunt 200. In the embodiment of FIGS.55A, 55D, length L₂, measured along the elongate central axis 231 of theshunt 200, is approximately 0.5 inches (1.27 cm) in the deliveryconfiguration. In other embodiments, L₂ may range between 10 mm to 30 mmin the delivery configuration. Further, in the embodiment of FIG. 55D,the inner diameter (ID) of the shunt 200 (e.g., lumen 207) measured in adirection orthogonal to axis 231, is approximately 0.0144 inches (0.3657mm). In other embodiments, the ID of the shunt 200 may range between0.002 inches (0.0508 mm) to 0.020 inches (0.508 mm). It should beappreciated that the ID, L₂ and any other length, width, or thicknessmay have any suitable dimension for implantation of the shunt 200 in thetarget site (e.g., IPS, CP angle cistern, or the like).

As previously described, the shunt 200 may be composed from any numberof biocompatible, compressible, elastic materials or combinationsthereof, including polymeric materials, metals, and metal alloys, suchas stainless steel, tantalum, or a nickel titanium alloy such as asuper-elastic nickel titanium alloy known as Nitinol. The shunt 200,particularly the elongated body 203 of FIGS. 55A-E, is composed ofNitinol. The shunt 200 further comprises one or more cuts 210 (e.g.,kerfs, slots, key-ways, recesses, or the like) along the elongated body203. The cuts 210 of the elongated body 203 may have a variety ofsuitable patterns, as shown in FIGS. 55A-60C. The cuts 210 and theirpatterns are preferably manufactured by laser cutting the elongated body203 of the shunt 200. Alternatively, the cuts 210 and their patterns maybe manufactured by etching or other suitable techniques. In theembodiment of FIG. 55C, each cut 210 may have a width of 0.001 inches(0.0254 mm). The width, length and depth of each cut 210 and patterns inthe elongated body 203 of the shunt 200, may comprise any suitabledimensions. The cuts 210 of the elongated body 203 are configured toincrease the flexibility of the shunt 200 for navigating tortuousanatomy during delivery and/or to assume a pre-determined configuration(e.g., secondary shape, for example helical/coil shape of FIGS. 6G-H,24A, 24E, 34A-B) when deployed and implanted at the target site.

Additionally, the shunt 200 comprises an inner liner 212 and an outerjacket 214, as better seen in FIG. 55E. The inner liner 212 and outerjacket 214 are composed of suitable implantable polymeric materials,such as polytetrafluoroethylene “PTFE”, polyethyleneterephthalate “PET”,High Density Polyethylene “HDPE”, expanded polytetrafluoroethylene“ePTFE”, urethane, silicone, or the like. Preferably, inner liner 212 iscomposed of materials that resist aggregation of CSF proteins and cellsflowing through shunt lumen 207 to maintain long-term shunt lumenpatency such as HDPE, PET, PTFE, or silicone. The inner liner 212 andouter jacket 214 are configured to cover—completely or partially—thecuts 210 of the elongated body 203, from within shunt lumen 207 and overshunt body 203, respectively; in such configuration, the elongated body203 becomes a frame that supports the inner liner 212 and outer jacket214. Shunt 200 with its inner liner 212, shunt body frame 203, and outerjacket 214 is impermeable to venous and sinus blood flow, and theintegrated liner-frame-jacket configuration maintains the flexibilityand pre-determined configuration that the cuts 210 provide to the shunt200.

Inner liner 212 provides a smooth surface within shunt lumen 207 andmaintains a laminar flow profile for CSF flowing through the shunt undernormal differential pressure (5-12 cm H2O) between the subarachnoidspace 116 and cistern 138. In addition to material selection criteriafor liner 212 previously described, maintaining laminar flow withinshunt lumen 207 further eliminates or reduces the risk of occlusion fromprotein accumulation and cell aggregation. Liner 212 can be configuredto line the interior of shunt body 203 using an extrusion process.Alternatively, the liner material can de deposited (e.g., using adispersion technique) on a mandrel (e.g., nickel coated copper);thereafter, the liner-coated mandrel can be placed within shunt body 203for application of outer jacket 214 and adhering inner liner 212 toshunt body 203, after which the mandrel can be withdrawn from shunt 200leaving inner liner 212 in place within shunt lumen 207. Without aninner liner 212, cuts 210 inside the lumen 207 can provide surfaces forproteins and cells to accumulate, which could occlude lumen 207 andprevent CSF from flowing from the subarachnoid space into the venoussystem.

Outer jacket 214 provides a smooth exterior surface to shunt 200, whichreduces the risk of thrombus formation in the IPS 102 compared to shunt200 with cuts 210 on the exterior surface of shunt body 203. As notedabove, the outer jacket 214 can comprise one or more implant-gradepolymers including, but not limited to, polyurethane orsilicone-polyurethane blends. In some embodiments, a gas or liquiddispersion of polymer is applied to shunt body 203 and inner liner 212,which forms the outer jacket 214 and bonds the inner liner 212, theshunt body 203, and outer jacket 214 together in an integratedconfiguration of shunt 200, for example, as shown in FIG. 55E.

Outer jacket 214 can completely cover the exterior surface of shunt body203; however, in other embodiments, the outer jacket can be placedselectively along portions of shunt body 203 to adhere inner liner 212to shunt body 203. By way of non-limiting example, a liquid dispersionof polymer or an epoxy-based adhesive can be placed at discretelocations along the length of shunt body 203 (e.g., proximal portion,middle portion, and/or distal portion of shunt body 203). Alternatively,the exterior surface of inner liner 212 can be coated with polymer oradhesive, and then placed within shunt body 203; the polymer or adhesivecan seep into cuts 210, completely or partially filling some or all ofthe cuts 210 along shunt body 203. In these embodiments, exteriorportions of the shunt body 203 material are exposed to the implant sitewithin the patient.

In the embodiment of FIG. 55E, the inner liner 212 may have a thinnessof 0.0007 inches (0.01778 mm), the elongated body 203 wall may have athinness of 0.0018 inches (0.04572 mm) and, the outer jacket 214 mayhave a thickness of 0.0005 inches (0.0127 mm). It should be appreciatedthat the inner liner 212, elongated body 203 and outer jacket 214 maycomprise any suitable dimensions.

FIGS. 56A-60C illustrate exemplary patterns of the cuts 210 of theelongated body 203 of the shunt 200, according to embodiments of thedisclosed inventions. As shown in FIGS. 56A-60C, the elongated bodies203 of shunts 200 comprise a variety of exemplary patterns of the cuts210. In these embodiments, the patterns of the cuts 210 are achieved bylaser cutting the elongated body 203 while rotating the body at aselected angle as the laser and body move with respect to one another.For example, with a laser oriented orthogonal to the longitudinal axisof the body 203 and with a laser capable of holding body 203 whilerotating and advancing the body relative to the fixture, the laser canbe activated and deactivated to form specific cut patterns in shunt body203. FIGS. 56B, 57C, 58C, 59C and 60C depict exemplary cut patterns in atwo dimensional view of their respective tubular elongated bodies 203 ofFIGS. 56A, 57A, 58A, 59A and 60A. In the embodiments of FIGS. 56A-58C,the laser cutting of the elongated body 203 creates 1.5 cuts 210 perrotation of the body, having a cut balance of about 210° of rotationwith laser on, and then 30° of rotation with laser off. In theembodiments of FIGS. 59A-C, the laser cutting of the elongated body 203creates 2.5 cuts 210 per rotation, having a cut balance of about 116° ofrotation with laser on, followed by 28° of rotation with laser off. Inthe embodiments of FIGS. 60A-C, the laser cutting of the elongated body203 creates 2.5 cuts 210 per rotation, having a cut balance of about116° on, 28° off. Further, while the pitch of the cut pattern isapproximately 0.0070 inches (0.1778 mm) in the embodiments of FIGS.56A-59C, each cut 210 may have a variety of widths; for example 0.0010inches (0.0254 mm) (FIGS. 56A-B), 0.0022 inches (0.05588 mm) (FIGS.57A-C), 0.0049 inches (0.12446 mm) (FIGS. 58A-C) or 0.0039 (0.09906 mm)(FIGS. 60A-C). In the embodiment of FIGS. 60A-C, each cut 210 has awidth of 0.00399 inches (0.10134 mm) and is oriented orthogonal to thetube's longitudinal axis, illustrating a zero-pitch pattern. It shouldbe appreciated that the above disclosed units are exemplary dimensions,angles and properties of the cuts 210 and their patterns, which are notintended to limit the embodiment of FIGS. 56A-60C.

FIGS. 61A-D illustrate an exemplary shunt 200′, constructed inaccordance with embodiments of the disclosed inventions. In theseembodiments, the tissue penetrating member 250 is fixedly coupled to thedistal portion 202 of the shunt 200′. The shunt 200′ further comprises acover 260 disposed over and slidably coupled to the tissue penetratingmember 250 and to the distal portion 202 of the shunt 200′. The cover260 comprises a first configuration, in which the cover 260 iswithdrawn, exposing the tissue penetrating member 250 of the shunt 200′(FIGS. 61A-B). The cover 260 further comprises a second configuration,in which the cover 260 is advanced, covering or hiding the tissuepenetrating member 250 (FIGS. 61C-D). The cover 260 may be actuated fromthe first to the second configuration by the deployment of the shunt200′ into the target site. For example, the cover 260 is disposed in thefirst configuration (FIGS. 61A-B) while the tissue penetrating member250 is piercing the IPS wall 114 and arachnoid layer 115 creating theanastomosis channel 140, as previously described (e.g., FIGS. 5E-I). Thedistal portion 202 of the shunt 200′ including the tissue penetratingmember 250 and the cover 260 are further advanced into the CP anglecistern until the cover 260 is also disposed within the cistern (notshown). Then, suitable withdrawal forces are applied to the shunt 200′creating an interface between the arachnoid layer 115 and the cover 260,actuating the cover 260 into the second configuration (FIGS. 61C-D), sothat the tissue penetrating member 250 is covered and hidden by thecover 260 when the shunt 200′ is deployed and implanted in the targetsite (not shown). Alternatively, the cover 260 may be actuated from thefirst to the second configuration using an actuation member (e.g.,tether 261, or the like) coupled to the cover 260, or any other suitablemethods. As a further alternative, penetrating element 250 can be madefrom bioresorbable/bio-absorbable materials (e.g., comprising magnesiumor zinc) that degrade over time and mitigate the risk of leaving a sharpelement implanted within the patient.

FIGS. 62A-D illustrate a shuttle element 570 for guarding piercingelements during delivery of the shunt into a target site, in accordancewith embodiments of the disclosed inventions. As shown in FIG. 62A, theshuttle element 570 comprises a proximal portion 574 having a proximalend opening 575 and a lumen 576, and a distal portion 572 having abumper 573. The proximal portion 574 forms a cover or sleeve-likeconfiguration suitable for a nesting interface with the puncture element250. The shuttle 570 is composed of any suitable biocompatiblematerials, previously described. Further, the bumper 573 is composed ofany suitable material configured to withstand meeting and engaging thepiercing element without being pierced, torn, and/or broken prematurely.Further, the bumper 573 may be covered or coated with a suitablepolymeric material that may assist the bumper 373 to withstand theengagement with the piercing element (e.g., polyurethane, silicone,ePTFE) and/or assist with the advancement of the bumper 373 through thevasculature (e.g., hydrophilic coatings or their like).

The shuttle 570 is configured to cover and guard piercing elementsduring delivery of the shunt 200 to the target site, protecting thepatient's vasculature from unintended tear or puncturing during deliveryfrom the venous access point in the patient to the target penetrationsite in the IPS wall 114. The shuttle 570 may be used in combinationwith any piercing element, for example, the tissue penetrating member250 of the shunt 200′, the tissue penetrating element 306 of thedelivery system 300, and/or the tissue penetrating member 350 of thedelivery catheter 304′. Additionally, the shuttle 570 may be used, forexample, with the embodiments of FIGS. 43A-44E and 47A-50B, such thatthe shuttle 570 may cover the deflated expandable element 390 (notshown) during the delivery of the shunt into the target site. It can beappreciated from FIGS. 44A and 62B-C that incorporation of the shuttleinto embodiments involving expandable balloons may further aid inballoon folding and reduce effective crossing profile while trackingthrough the vasculature.

FIGS. 62B-D depict an exemplary interface of the shuttle 570 with theshunt 200′ and tissue penetrating member 250. As shown in FIG. 62B, thetissue penetrating member 250 is disposed within the lumen 576 of theshuttle 570 during advancement of the shunt 200′ through the deliverycatheter 304. The proximal portion of the shuttle 570 covers andprotects the tissue penetrating member 250 during advancement into thetarget site. The tissue penetrating member 250 may meet and engage thebumper 573 of the shuttle 570 during delivery of the shunt 200′. Theshuttle 570 is advanced by the engagement and advancement of the tissuepenetrating member 250 (e.g., pushing the shuttle), by being coupled tothe delivery guidewire 308 (e.g., axial translation of the guidewire),by being advanced with a plunger or push element (not shown), or anyother suitable actuation mechanisms and methods. For example, theshuttle 570 may be slidably coupled to the guidewire 308 comprising afirst stop 308′ and a second stop 308″, as shown in FIG. 62D. In theembodiments where the shuttle 570 is slidably disposed over theexemplary guidewire 308 of FIG. 62D, the bumper 573 is disposed betweenthe first 308′ and second 308″ stops, so that advancement of theguidewire 308 causes the first stop 308′ to engage the bumper 573 thusadvancing the shuttle 570 (FIG. 62D), and withdrawal of the guidewire308 causes the second stop 308″ to engage the bumper 573 thereforewithdrawing the shuttle 570 (not shown). The first stop 308′ and secondstop 308″ may be constructed for varying degrees of interference withthe bumper 573 such that a predetermined amount of tensile orcompressive force would allow the bumper 573 to bypass the first stop308′ or second stop 308″ selectively throughout the course of a givenprocedure. Once the shunt 200′ is disposed within the IPS 102, shown inFIG. 62B, the delivery catheter 340 and/or shunt 200′ are withdrawnexposing the tissue penetrating member 250, or the shuttle 570 isadvanced exposing the tissue penetrating member 250. Alternatively, thewithdrawal of the delivery catheter 340 and/or shunt 200′, and theadvancement of the shuttle 570 occurs simultaneously or consecutively toexpose the tissue penetrating member 250. Additionally, the shuttle 570may be configured with a slit along its longitudinal axis thatfacilitates side-exit of the tissue penetrating member 250 through theapplication of sufficient axial and/or bending loads. The tissuepenetrating member 250 is then oriented and advanced towards the IPSwall 114, with any of the methods described herein, to pierce the IPSwall 114 and the arachnoid layer 115 creating the anastomosis channel140 (FIG. 62D).

FIGS. 63A-G illustrate another exemplary shunt 200 constructed andimplanted according to embodiments of the disclosed inventions. Theshunt 200 includes the anchoring mechanism 227 in the proximal portion204, the anchoring mechanism 229 in the distal portion 202, and theelongate body 203 extending therebetween. The anchoring mechanisms 227and 229 include a flared-basked configuration (FIGS. 63A-C). Theflared-basked anchoring mechanisms 227 and 229 include a plurality ofrespective elements 227 a and 229 a manufactured by selective cuttingthe respective proximal 204 and distal 202 portions of the shunt 200(FIGS. 63D-F), using any suitable cutting method (e.g., laser cutting).FIGS. 63E-F depicts detailed exemplary patterns of the cuts of therespective proximal 204 and distal 202 portions of the shunt 200. Theplurality of respective elements 227 a and 229 a can be biased into aradially outward configuration for deployment (e.g., as shown in FIG.63G), and compressed in a delivery configuration until deployment of theshunt 200. While the plurality of respective elements 227 a and 229 a donot incorporate an liner or outer jacket as shown in FIG. 63G, inalternate embodiments the plurality of respective elements 227 a and 229a and the elongated body 203 of the shunt 200 are covered by a coatingand/or liner, as for example, the liner 214 described in FIG. 55E. Theliner is configured to allow the respective elements 227 a and 229 a toexpand radially outward in the deployed configuration of the shunt 200,assuming the flared-basked configuration of the anchoring mechanisms 227and 229, as for example, shown in FIGS. 63A-C, 63G. Alternatively, or inaddition to the lined anchoring mechanisms 227 and 229, the inner liner212 extends out the longitudinal axis of shunt body 203 at the proximaland/or distal end of shunt body 203 by a predetermined distance rangingfrom one to several millimeters. For example, on the distal end portion203 of the shunt, the liner can extend approximately 3 mm above theportion of anchoring mechanism 229 that rests atop arachnoid layer 115,thereby maintaining the shunt lumen 207 separated or away from arachnoidcells. By way of further example, in the proximal end portion 204 of theshunt, the liner can extend from shunt body 203 into or onto valve 209,without lining proximal anchoring mechanism 227.

As shown in FIG. 63A, the deployed anchoring mechanism 227 engages thejugular bulb 108, the IPS wall 117, and/or another portion of the IPS102, anchoring the proximal portion 204 of the shunt 200 within thejugular vein 106, so that the valve of the proximal portion 204 (notshown) is disposed within the jugular vein 106. Alternatively, theanchoring mechanism 227 may engage the IPS walls 114 and 117 at thejunction 118 (not-shown). The deployed anchoring mechanism 229 securesthe distal portion 202 of the shunt 200 within the CP angle cistern 138,so that CSF flows through the implanted shunt 200 into the jugular vein106. FIG. 63B-C depict further perspective views of the shunt 200.

FIGS. 64A-C illustrate another exemplary distal anchor of the shunt,constructed and implanted according to embodiments of the disclosedinventions. As shown in FIG. 65A, the tissue penetrating member 250 isadvanced from the IPS 102, piercing the IPS wall 114 and arachnoid layer115, creating the anastomosis channel 140 into the CP angle cistern 138.The distal portion 202 of the shunt 200′ is advanced into the CP anglecistern, so that the distal anchoring mechanism 229 is deployed,securing the distal portion 202 of the shunt 200′ at the target site.The deployed anchoring mechanism 229 expands the distal portion 202 ofthe shunt 200′, and is configured to assume a larger inner diameter ID₁than the inner diameter ID₂ of the elongated body 203 of the shunt 200′,as shown in FIG. 64B. The anchoring mechanism 229 comprises a distaledge 229′ configured to invert and/or be disposed radially inward in thedeployed configuration (FIG. 64B). Alternatively, the anchoringmechanism distal edge 229′ may be configured to evert and/or be disposedradially outward in the deployed configuration (FIG. 64C). It should beappreciated that the anchoring mechanism 229 of FIGS. 64B-C may be usedwith any of the embodiments of the shunts described herein, asappropriate.

FIGS. 65A-D illustrate an exemplary delivery catheter 304″ fordelivering the shunt 200 into a target site of a patient, constructed inaccordance with embodiments of the disclosed inventions. For ease inillustration, the features, functions, and configurations of thedelivery catheter 304″ that are the same as in the assembly 300 of FIGS.3B and 4A-D, in the assembly 300′ of FIGS. 5A-J, and/or in the catheter304′ of FIGS. 43A-D, are given the same reference numerals. The deliverycatheter 304″ is dimensioned to reach remote locations of thevasculature and is configured to deliver the shunt 200 percutaneously tothe target location (e.g., inferior petrosal sinus). The deliverycatheter 304″ may comprise variable stiffness sections (e.g., varyingratio of material, including selective reinforcement, such as braids,coils, or the like) suitable to provide sufficient “pushability” and“torqueability” to allow the catheter 304″ to be inserted, advancedand/or rotated in the vasculature to position the distal portion 344 ofthe catheter at the target site within the IPS 102. Further, the distalportion 344 should have sufficient flexibility so that it can track andmaneuver into the target site. Variable stiffness in the catheter 304″is achieved, for example, by locally varying the properties and/ordistribution of the materials used and/or varying the durometer orthickness of the materials during the process of manufacturing. By wayof non-limiting examples, the materials used in manufacturing thecatheter 304″ may include polyether block amide (Pebax®) and Nylon, andany other suitable materials, such as the materials previously describedfor manufacturing the catheter 304′. It should be appreciated that whenappropriate, the delivery catheter 304″ may be used in combination withthe delivery assembly 300/300′ also previously described.

The distal portion 344 of the delivery catheter 304″ comprises thetissue penetrating member 350 having lumen 355 fluidly coupled to thelumen 305 of the delivery catheter 304″ (FIG. 65C). The shunt 200 isconfigured to be deployed into the target site via lumens 305, 355, whenthe anastomosis channel 140 is created (not shown). It should beappreciated that when using the delivery catheter 304″ to deliver anddeploy the shunt 200 into the target site, the tissue penetratingelement 306 of the delivery assembly 300 and/or the tissue penetratingmember 250 incorporated in the shunt 200′ may not be required.

The delivery catheter 304″ further comprises a lumen 314 configured foradvancement of a guidewire 318, supplying and/or withdrawing fluid tothe vasculature and/or any other suitable function (FIGS. 65B-E). Theelongated guidewire 318 includes a flattened profile, as seen in thecross-sectional views of the wire 318 in FIG. 65B and FIG. 66, and thewire 318 is formed of Nitinol. In other embodiments, the wire 318 maycomprise any suitable profile and materials. The delivery catheter 304″may be advanced over the wire 318 extending through the lumen 314, untilthe distal end portion 344 of the delivery catheter 304 is positioned inthe IPS 102 (not shown).

FIGS. 67A-D illustrate exemplary cross-sectional views of the deliverycatheters for delivering the shunt 200 into a target site of a patient,constructed in accordance with embodiments of the disclosed inventions.FIG. 67A depicts a cross-sectional view of the delivery catheter 304comprising a tubular interface having an outer tubular member 364 and aninner tubular member 365 coaxially disposed within the outer tubularmember 364. The coaxial tubular interface of the catheter 304 comprisesthe lumen 305 configured to deliver the shunt 200 into the target site,and the lumen 314 configured for advancement of guidewires, supplyingand/or withdrawing fluid to expandable members (e.g., balloons, or theirlike) or to the vasculature and/or any other suitable function. FIG. 67Bdepicts a cross-sectional view of the previously described deliverycatheter 304″ of FIGS. 65A-E. FIGS. 67C-D depict cross-sectional viewsof the delivery catheter 304′ comprising the lumen 305 configured todeliver the shunt 200 into the target site, and two additional lumens, aguidewire lumen 315 and an inflation lumen 317. It should be appreciatedthat any other configuration of the delivery catheter and lumenssuitable for delivering the shunt 200 into the target site may be used.

Lumens of the catheter embodiments depicted in FIGS. 65A-67D can beconfigured to conform to the various delivery assembly 300 elements usedsuch catheters. Lumen 314 of delivery catheter 304″ depicted in FIG. 65Bcomprises a crescent shaped profile, distinct from the flattened profileof wire 318. In other embodiments, the profile of all or a portion oflumen 314 can be configured to more closely match the exterior profileof wire 318. For example, the bottom left and right portions of lumen314 shown in FIG. 65D can be formed to match the straight and anglededges on the bottom portion of the wire 318. As another example, lumen314 can match the profile of the wire 318 depicted in FIG. 66. Conformedcatheter lumens can eliminate the risk that the element passing throughinadvertently changes orientation or trajectory within the catheterduring the shunt implant procedure. In addition, any combination ofconformed lumens can be used with or in place of the circular andcrescent lumen 314 embodiments shown in FIG. 67A-D. It will beappreciated by those of skill in the art, however, that certain lumen314 configurations (e.g., crescent lumen versus rectangular lumen ofequal size) can conserve more cross-sectional area of the catheter toaccommodate other lumens and componentry.

The lumens of the catheter embodiments depicted in FIGS. 65A-67D anddisclosed elsewhere in this application (e.g., delivery catheter 304,guide catheter 320) can include a liner to increase the lubricity of thedelivery assembly 300 and reduce friction between the specific catheterlumen and delivery system components delivered through such lumen. Thecatheter liner may comprise homopolymers, copolymers or polymer blendscontaining polyamides, polyurethanes, silicones, polyolefins (e.g.,polypropylenes, polyethylenes), fluoropolymers (e.g., FEP, TFE, PTFE,ETFE), polycarbonates, polyethers, PEEK, PVC, and other polymer resins.The liner thickness can range from approximately 0.0005 inches to 0.003inches. In addition, the catheter embodiments can include hydrophiliccoatings commonly known in the art to further increase the lubricity andnavigability of the delivery assembly 300 components within the patient.

In the embodiments of the disclosed inventions, a method for relieving apatient's elevated intracranial pressure by implanting the shunt200/200′ in the patient is provided. The shunt 200/200′ comprising oneor more cerebrospinal fluid (CSF) intake openings 201 in a distalportion 202 of the shunt 200/200′, the valve 209 disposed in a proximalportion 204 of the shunt 200/200′, and the lumen 207 extending betweenthe one or more CSF intake openings 201 and the valve 209 (e.g., asshown in FIG. 6). The method comprises: introducing the deploymentsystem 300/300′ including the tissue penetrating element 306/250/350 andthe shunt 200 from a venous access location in the patient; navigatingthe deployment system 300/300′, including the penetrating element306/250/350 and shunt 200/200′, from the venous access location to atarget penetration site within the IPS 102 of the patient, via thejugular vein (JV) 106 of the patient; assessing a trajectory of thetissue penetrating element 306/250/350 at the target penetration sitefrom the IPS 102 into the angle cistern 138 of the patient; advancingthe tissue penetrating element 306/250/350 through dura IPS wall 114 andarachnoid tissue layer 115 at the target penetration site, and into theCP angle cistern 138; advancing the distal portion 202 of the shunt200/200′ into the CP angle cistern 138 through an opening (e.g.,anastomosis channel 140) in the respective dura IPS wall 114 andarachnoid tissue layer 115 created by the tissue penetrating element306/250/350; deploying the distal anchoring mechanism 229 of the shunt200/200′ in the CP angle cistern 138; withdrawing the delivery system300/300′ from the target penetration site towards the JV 106, whereinthe shunt 200/200′ is expelled from the delivery system 300/300′ andthereby deployed in the IPS 102 as the delivery system 300/300′ iswithdrawn toward the JV 106; deploying the proximal anchoring mechanism227 of the shunt 200/200′ about a junction 118 of the JV 106 and IPS102, such that the proximal portion 204 of the shunt 200/200′ isoriented away from a medial wall of the JV 106; and removing thedelivery system 300/300′ from the patient, wherein the deployed shunt200/200′ provides a one-way flow path for CSF to flow from the CP anglecistern to the JV 106 via the shunt lumen 207 in order to maintain anormal differential pressure between the patient's subarachnoid spaceand venous system. The method may further comprise confirming that thetissue penetrating element 306/250/350 has accessed the CP angle cistern138 by withdrawing CSF from the CP angle cistern 138 through thedelivery system 300/300′ prior to withdrawing the delivery system300/300′ from the patient.

In the embodiments of the disclosed inventions, a method for treatingnormal pressure hydrocephalus (NPH) using the shunt 200/200′ isprovided. The shunt 200/200′ comprising one or more cerebrospinal fluid(CSF) intake openings 201 in the distal portion 202 of the shunt 200,the valve 209 disposed in the proximal portion 204 of the shunt200/200′, and the lumen 207 extending between the one or more CSF intakeopenings 201 and the valve 209, the lumen 207 having an inner diameterin a range of 0.008″ to 0.014″. The method comprises: deploying theshunt 200/200′ in a body of an NPH patient so that the distal portion202 of the shunt 200/200′ is at least partially disposed within the CPangle cistern 138 of the patient, the body 203 of the shunt 200/200′ isat least partially disposed within the IPS 102 of the patient, and theproximal portion 204 of the shunt is at least partially disposed within,or proximate to, the jugular vein (JV) 106 of the patient, wherein theshunt valve 209 opens at a pressure differential between the CP anglecistern 138 and JV 106 in a range of 3 mm Hg to 5 mm Hg, so that, afterdeployment of the shunt 200/200′, CSF flows from the CP angle cistern138 to the JV 106 via the shunt lumen 207.

When the shunt 200/200′ is deployed, the proximal portion 204 of theshunt 200/200′ may be disposed adjacent to a jugular bulb 108.

The methods and devices disclosed herein provide a number of significantadvantages relative to other methods and systems intended to treathydrocephalus or relieve elevated ICP.

Conventional VP shunt placement surgery is an invasive procedureperformed under general anesthesia and typically requires about three tofive days hospitalization. During the procedure, the physician makes abore hole in the patient's skull and then passes a catheter through suchhole and further, through brain tissue (e.g., cerebral cortex greymatter, brain white matter, ventricles) to access CSF within thecerebral ventricles. Ventricular catheter placement typically requirescoagulating the cortex of the brain and passing the catheter throughcerebral cortex and subcortical white matter one or several times.Thereafter, the ventricular catheter is attached to an inflow portion ofa valve mechanism that the physician implants underneath the patient'sscalp, often behind the ear. The outflow portion of the valve mechanismis attached to a silicone catheter that is tunneled under the patient'sskin down through the neck and into the abdomen. The implanted shuntprovides a one-way flow path for CSF to travel from the patient'sventricle and into the peritoneal cavity.

VP shunts are prone to clogging, particularly in the ventricularcatheter and peritoneal tubing. As excess CSF is removed from theventricles through the catheter, the ventricles become smaller. Often,as the ventricles shrink, the choroid and other cells of the surroundingventricle shrink down around the CSF inlets of the catheter and obstructthe flow of CSF into the VP shunt. The peritoneal tubing often clogsfrom cell ingrowth (e.g., endothelial cells) and/or clogs fromincorporation into the abdominal wall. VP shunt placement surgery has arelatively high rate of infection especially when compared to minimallyinvasive, endovascular procedures. VP shunts are subject to a siphoningeffect due to the long, hydrostatic column created between the CSFinflow (i.e., ventricle) and outflow (i.e., peritoneum) locations of theimplanted shunt. Draining CSF too rapidly or draining too much CSF fromthe ventricles presents significant risk to the patient from, e.g.,collapsed ventricles or subdural hematoma. Complicated anti-siphoningvalves have been developed in attempt to mitigate the siphoning effectin VP shunts.

In contrast, by using an endovascular deployment method and deployingshunt 200 from within IPS 102 into CP angle cistern 138 such that CSFdrains into the jugular bulb or vein, the risks and cloggingcomplications due to invasive surgery, surrounding brain tissues,infection, and siphoning effect can be eliminated or significantlymitigated. In many patients, particularly those less than 70 years old,there is little or no space between the arachnoid layer and brainparenchyma within the subarachnoid space to accommodate an endovascularshunt in a venous sinus other than IPS 102. In such cases, shuntdeployment techniques and shunt features move brain parenchyma and/orcreate or augment a cistern in the subarachnoid space for CSF to poolfor inflow to the shunt. Such techniques increase the risk of injury tobrain tissue and increase the risk of subsequent shunt clogging at theproximal end from surrounding brain tissue. The methods, systems, anddevices disclosed herein significantly reduce or eliminate these risks.

Some advantages of the endovascular access system and method fornavigating a catheter into a target site (e.g., inferior petrosal sinus)and placing an endovascular shunt to drain CSF from a cerebral cistern(e.g., cerebellopontine (CP) angle cistern) to treat communicatinghydrocephalus including NPH, and pseudotumor cerebri, are disclosedherein, thereby minimizing undesired effects of traditional VPSplacement, avoiding boring into a patient's skull, coagulating thecortex of the brain, passing a shunt catheter through cerebral cortexand subcortical white matter one or several times, and other invasivesurgical techniques used in current hydrocephalus treatments.

The anatomy of CP angle cistern 138 and its proximity to IPS 102 make ita preferred location for deploying an endovascular CSF shunt, comparedto the sigmoid sinus or other intracranial venous sinuses (e.g., thetransverse sinus, the cavernous sinus, the sagittal sinus, and/or thestraight sinus). CP angle cistern 138 typically features a largeCSF-containing space and a greater separation between the arachnoidlayer and the closest surrounding brain parenchyma than any other CSFcisterns accessible from venous conduits. Accordingly, positioning shunt200 within CP angle cistern 138 is easier and more fault tolerant thanpositioning the shunt within other cisterns, and the rate at which CSFcan be communicated to venous circulation is greater on account of thelarger pool of CSF within CP angle cistern 138.

Venous blood flow rates in jugular vein 106 can be significantly higherthan the blood flow rates in larger diameter dural venous sinuses (i.e.,sagittal, sigmoid, straight, transverse), which favor long-term shuntpatency of the disclosed embodiments compared to other implantlocations.

In addition, the anatomy of IPS 102 facilitates long-term stability ofshunt 200. The relatively long length and narrow diameter of IPS 102provides a natural housing to accommodate shunt 200 along its length.The foundation provided by the grooved portion of the clivus bone thatsurrounds about two-thirds of the IPS circumference further supportslong-term stability of the shunt 200, and presents a stable platformthat delivery systems disclosed herein can leverage during shunt implantprocedures. The situation differs in the other venous sinuses, which arenot as well adapted naturally to house a shunt. Further, if IPS 102occludes due to occupation by shunt 200, thereby restricting orpreventing blood flow through IPS 102, there is little to no risk to thepatient given the relatively minor role of IPS 102 in the overallintracranial venous blood circulation system. Occlusion of largerdiameter venous sinuses (e.g., sagittal, sigmoid, straight, transverse),on the other hand, poses a serious risk for the patient.

Further, despite the advantages of the endovascular approach to deliverand implant the shunt according to the disclosed inventions, it shouldbe appreciated that other delivery methods may be used to deliver andimplant the shunts described herein, such as, using open and/or invasivesurgical procedures.

It should be appreciated that prior to use in humans, the embodiments ofthe disclosed inventions can be deployed and tested in suitable animalsurrogates having venous vascular and intracranial subarachnoid featuresthat resemble or closely approximate the IPS and CP angle cistern inhumans. Pigs (e.g., Yorkshire pigs or Yucatan mini-pigs) have a suitabledeployment site for testing embodiments of the disclosed inventions. Inthe pig model, the system can navigate a shunt to the basilar sinus(e.g., via the internal jugular vein or venous vertebral plexus), anddeploy the shunt through dura and arachnoid tissues to access CSF-filledsubarachnoid space (e.g., basilar cisterns, pontine cisterns) fortesting. Suitable surrogates for the IPS and CP angle cistern in humansare feasible in other animal models (e.g., dogs and primates).

Although particular embodiments have been shown and described herein, itwill be understood by those skilled in the art that they are notintended to limit the present inventions, and it will be obvious tothose skilled in the art that various changes, permutations, andmodifications may be made (e.g., the dimensions of various parts,combinations of parts) without departing from the scope of the disclosedinventions, which is to be defined only by the following claims andtheir equivalents. The specification and drawings are, accordingly, tobe regarded in an illustrative rather than restrictive sense. Thevarious embodiments shown and described herein are intended to coveralternatives, modifications, and equivalents of the disclosedinventions, which may be included within the scope of the appendedclaims.

What is claimed is:
 1. A system for treating a patient, the systemcomprising: an elongate guide member; a delivery catheter configured foraccessing a cerebrospinal fluid (CSF)-filled intracranial subarachnoidspace (SAS) from a venous sinus, respectively, of the patient, thedelivery catheter comprising a deflecting element configured fordeflecting a tissue penetrating member toward a target penetration sitein a wall of the venous sinus to create an anastomosis between thevenous sinus and the SAS, and a guide member lumen configured forreceiving the elongate guide member; a stabilizing member coupled to theelongate guide member, wherein the stabilizing member is configured forengaging a wall of the venous sinus to thereby stabilize a distal endportion of the delivery catheter proximate the target penetration site;and an implant configured for being advanced through, and deployed from,the delivery catheter, the implant comprising an implant proximalportion, an implant distal portion having a distal anchoring mechanismconfigured for securing the implant distal portion within the SAS, andan implant lumen in fluid communication with one or more distal openingsin the implant distal portion and with one or more proximal openings inthe implant proximal portion.
 2. The system of claim 1, wherein thetissue penetrating member comprises a tissue penetrating distal tip ofthe delivery catheter.
 3. The system of claim 1, wherein the tissuepenetrating member comprises a stylet configured to be advanced throughthe delivery catheter, the stylet having a tissue penetrating distaltip.
 4. The system of claim 1, wherein the tissue penetrating membercomprises a beveled or Quincke distal tip of the delivery catheter or ofa stylet configured to be advanced through the delivery catheter.
 5. Thesystem of claim 1, wherein the delivery catheter further comprises aradiopaque marker configured to indicate an orientation of the distalportion of the delivery catheter relative to the target penetrationsite.
 6. The system of claim 1, wherein the stabilizing member comprisesa coil, a stent, an expandable balloon, or a combination thereof.
 7. Thesystem of claim 1, wherein the delivery catheter further comprises adelivery lumen and a distal opening in communication with the deliverylumen, wherein the implant is configured to be advanced through thedelivery lumen and out the distal opening into the anastomosis and SAS,respectively.
 8. The system of claim 7, further comprising an elongatepusher member, wherein the tissue penetrating member is coupled ordisposed on a distal portion of an elongate pusher member, and whereinthe elongate pusher member is configured to be advanced from the distalopening of the delivery catheter to create the anastomosis.
 9. Thesystem of claim 1, wherein the deflecting element comprises a ramp. 10.The system of claim 1, wherein the implant comprises a valve disposed inthe implant lumen.
 11. The system of claim 10, wherein the implant valveis configured to prevent back flow of blood through the implant lumeninto the SAS.
 12. The system of claim 10, wherein the valve isconfigured to regulate a flow of CSF through the implant lumen.
 13. Thesystem of claim 7, wherein the implant distal anchoring mechanism isconfigured to self-expand within the SAS.
 14. A system for treating apatient, the system comprising: an implant comprising an implantproximal portion, an implant distal portion having a distal anchoringmechanism configured for securing the implant distal portion within acerebrospinal fluid (CSF)-filled intracranial subarachnoid space (SAS)of the patient, and an implant lumen in fluid communication with one ormore distal openings in the implant distal portion and with one or moreproximal openings in the implant proximal portion; a conduit comprisinga tubular configuration, the conduit having a conduit proximal portion,a conduit distal portion, and a conduit lumen extending between anopening in the conduit proximal portion and an opening in the conduitdistal portion, wherein the conduit is configured for deployment in avenous sinus of the patient proximate a target penetration site in awall of the venous sinus adjacent the SAS, the conduit furtherconfigured to house the implant when the conduit is deployed in thevenous sinus; and a tissue penetrating element configured for creatingan anastomosis through the venous sinus wall to access the SAS.
 15. Thesystem of claim 14, wherein the conduit comprises a self-expandingscaffold configured to expand within the venous sinus when the conduitis deployed therein from a delivery catheter.
 16. The system of claim14, wherein the conduit comprises an anchoring mechanism for securingthe conduit within the venous sinus.
 17. The system of claim 14, whereina distal portion of the conduit lumen is curved so as to direct thepenetrating element toward the the target penetration site.
 18. Thesystem of claim 14, wherein the implant comprises a valve disposed inthe implant lumen.
 19. The system of claim 18, wherein the implant valveis configured to prevent back flow of blood through the implant lumeninto the SAS.
 20. The system of claim 14, wherein the valve isconfigured to regulate a flow of CSF through the implant lumen.